Engineering a car in Automation is relatively easy. Making a car to cater to a specific market can be a tad more difficult however. When engineering a car, it's important to remember that everything affects everything. Changing the engine cam profile is one major vector, for example. This guide will try to cover each step of the way, and hopefully get you started on making cars that actually sell.

This guide is not intended to show you how to replicate a specific engine/car. Nor is it intended to be used as a guide to make a "realistic" car. Instead, we'll show you how to actually make a functional engine/car, and talk about the little, less than obvious tricks of the car designer that can help fix any issues you may be running into.

Note: LC V3 Patch 7 includes good information presented in tooltips. It it highly suggested reading through the chart tooltips, as well as the item tooltips available by clicking on the item headers. This guide is supplemental, and really just intended to give pointers on how to do things.

Also: Any date I mentioned in this guide for part unlock is specifically for Sandbox purposes with 0 techpool. You can accelerate unlock dates for different technology in the Light Campaign with R&D. This guide, except for the sections focused on it are specifically targeted towards the Sandbox mode, with some reference to the Light Campaign mixed in.

The model (chassis) of the car will determine quite a lot of the characteristics of the car, with most models supporting multiple trims (or body types) that can fit on the model chassis. Some chassis types for example can be used as a Coupe or a Van and everything in between. Some can only be used for a single trim. All models and trims have various stats as well, which are worth paying attention to.

Going from top left to bottom right in left/right reading order. Note, the UI has been overhauled, and the order has changed slightly, but the information presented is still the same.

• Year and Body Trim: When the body is supposed to become commonly available to manufacture. Also defines the specific body type the car actually is. Different demographics prefer different types of car body. Most sports car buyers aren't looking for a van or SUV for example. Older body types also lose value over time.
  
• Wheel Base: How far apart the front axle is from the rear axle. A higher number here generally means a bigger car. This number is always shown on the thumbnail of the car as well in your preferred system of measurement.
  
• Acceptable Engine Location: Should be simple. This determines if the engine is in the front, trunk (rear), or in the case of some cars, mounted under the passenger cabin rear (mid engine). Where the engine is mounted will have a major influence on how big the engine can be, depending on the model. This can be a major influence on the weight balance of the car, since the engine block is usually the heaviest part of the car.
  
• Drag: This is a number demonstrating on how much drag coefficient the unmodified body has. More drag makes the car overall less efficient at accelerating, maximum speed, and good fuel economy.
  
• Track Width: Distance between the wheels going across the car. Bigger means a bigger car. This assumes there's no tire offset going on here either, as you can make the track width slightly longer by doing so.
  
• Doors: How many doors the car has, obviously. More doors usually make the car more practical. If the car has three or five doors, the back can most likely completely open, such as a hatchback or a wagon type car.
  
• Lift: How much lift the car generates at higher speed, assuming there is no undertray installed. Lift can be good, or bad depending on the target.
  
• Cabin Size: How much room there is in the passenger cabin with an unmodified body. More space usually means more comfort, and can be considered luxurious.
  
• Cargo Volume: How much the car can carry of things which aren't people. This can usually be modified by the suspension type.
  
• Seat Rows: How many rows of seats the car can support. Generally single row cars are niche Coupes.
  
• Convertible (Potentially): Defines the type of top the convertible trim has. Soft tops are marginally worse than hard tops statistically, but also much cheaper and lighter than a hard top.
  
• Code(ish) Name: This is the name of the model of the car in the back end. This is usually irrelevant for players, but if you have a bug with the model of car, it's easier for the devs to find and fix the issue if they know this instead of "the '05 Coupe that might also be a van".

Once you've selected your car model, and year, you will then have to setup the basic assembly on how the car is actually put together, such as what is the car actually made of. This step will also likely have a large influence on how well accepted the car is for the target market, as the panels, suspension, and engine placement are major portions of what makes a car appeal to a certain market. This cannot be changed. All trims are based off of this chassis. You can't, for example, change the suspension type because it would suit the different body trim better.

The panels, or "upper shell" or "thing everyone sees" is what the actual car body is made of, from basic steel, to fancy carbon fiber. This can have a large impact on most of the metrics that the car has.

(In order of unlock date.)

• Steel: Basic, raw pressed steel. Steel is a good choice for cheaper cars which are intended to be mass produced. Excepting the massive upfront costs to actually get a factory large enough with steel presses, this is one of the cheapest body panels to use, while also the heaviest. It's relatively safe as well. It does corrode severely compared to other bodies however.
  
• Aluminum: Full body aluminum. Aluminum is a shell which early in the game will prohibit mass production of the car initially. It's relatively light compared to steel, very resistant to corrosion, and quite a bit expensive compared the other body types. It's highly prestigious, and continues to be the highest prestige paneling throughout the entire game, until carbon fiber comes along. Limited production starts in '82 and mass produced in '09 with presses.
  
• Fiberglass: Very light, and extremely cheap to tool a factory for, but can't be mass produced without factory add-ons for quite a long time and the material itself is slightly expensive. Fiberglass is overall not a fantastic body type for cars which aren't racecars, or cars with weak engines (thereby saving weight, making the engine practical), noise and extreme lack of safety being major contributors. Otherwise the benefit it can provide is significant. This panel type will actually cost prestiege, since it will make the car feel/sound like plastic. An option in '55. Also able to be produced with limited production in '70, using SMC.
  
• Partial Aluminum: This is a steel bodied car, with certain parts made of aluminum. The benefits you get from this are some weight savings, and some extra corrosion resistance, with no cost to most statistics except a slightly higher material and tooling cost. An option in '85.
  
• Partial Carbon Fiber: An aluminum body, with the hood, bumpers and other trimmings replaced with carbon. Available in '94, and requires two factory addons to maximize production efficiency in '09, still capped to limited production.
  
• Carbon Fiber: This supercar body only becomes available in '93, and remains very difficult to mass produce. This is the lightest body type available, and also the most expensive. It's usually only going to be affordable to the highest class of premium buyers, but if you want a car to go 0-60 MPH (or 0-100 KM/H) in record times, then this is the body to use. An option in '94. Limited in '05 with a carbon plant.
  
• Treated Steel: Steel treated in chemical baths. Slightly lighter than regular steel, and slightly more corrosion resistant and a bit stronger. This comes at the cost of needing a steel treatment facility which has a size floor of Large or bigger. It's a choice in '99.

The chassis is what the actual panels, and everything else are mounted to. This is a large factor in most fields.

• Ladder: This chassis is essentially a series of steel boxes welded together to make the chassis with the paneling built on top. This is a very simple, very heavy chassis to assemble. It's actually not too bad for most types of heavy duty vehicles, but it's usually a poor choice for smaller, sportier cars. This type of chassis is relatively unsafe, since the boxes the frame is made of tend to collapse in a crash. Ladder frames are prone to twisting too. They are the only choice for mass production until the '50s.
  
• HD Ladder: Heavy Duty Ladder frame, similar to the regular ladder frame but more sturdily built up. Heaviest chassis in the game, but is a good choice for early, safer cars before monocoque is accessible, and overall is a good general choice for vehicles that need to be built up more like vans and trucks.
  
• Space Frame: Hand assembled pipes make up nearly the entirety of the frame of this body. Overall, slightly safer than a Ladder frame, but at no point can be mass assembled. This is usually okay in the earlier years for sportier cars or for super/hypercars which usually won't have many buyers, until Monocoque comes along, and starts to compete with this type of chassis. Space Frames are designed to resist twisting motion, and work very well for sports cars, especially high end trims, even after Monocoque is out.
  
• Monocoque: A single stamped piece of chassis. This is a common body type, and is overall a very safe type of chassis as well. It's lighter than a ladder frame, but needs steel presses in order to be used (with exceptions, usually special versions which avoid steel). Later down the line additional types of steel are available, and other material types become available even later down the line such as aluminum and carbon fiber. Monocoques have minor levels of twisting, but in general don't twist as much as a ladder, and can be stiffened with high quality materials. An option in '51.
  
• Semi Spaceframe: This chassis is made completely of aluminum. It's a relatively expensive, but light option which is quite viable for sports cars, and supercars. This chassis is also highly corrosion resistant, and can be used on offroad vehicles if so desired. It does need a special assembly building to use. A choice in '00.

Different chassis types can be made of different types of material. Most chassis types can only be made of steel and their improved variants.

• Steel: Basic steel. It can be used on the majority of chassis, and is relatively cheap but it rusts.
  
• Galvanized Steel: Steel, which has gone through galvanizing, or has had a layer of "sacrificial" zinc applied. It's very similar to raw steel, but slightly more corrosion resistant. Relatively cheap as well, though you need a galvanization plant.
  
• Corrosion Resistant Steel: Stainless steel. Much more resistant to corrosion at the cost of higher material cost and more production units due to extra seals. This doesn't require any extra add on facilities though. An option in '60.
  
• Carbon Fiber: A very light carbon Monocoque body. Extremely expensive to put together, but works amazing for high end sports cars. Option in '88. Limited in '14 with a plant.
  
• AHS Steel: Advanced High Strength Steel. A special steel alloy, which is overall stronger, and stiffer than regular steel, making the car safer, slightly lighter, and generally better at the cost of the tooling required to make. A choice in '95.
  
• Glued Aluminium: It's possible to make a Monocoque chassis out of glued aluminum configuration which isn't a Semi Spaceframe chassis. This involves some steel, with aluminum pieces welded or bolted or glued using aviation grade glue to the steel. It's extremely light, but very production intensive, and will take quite a bit of time to assemble. A choice in '00.
  
• Light AHS Steel: A lighter variant of AHS steel intended to reduce overall mass. It's available in 2001. It's slightly less safe than the standard AHS alloy, but does save a bit of weight.

Choosing where the engine is mounted, and the direction it's mounted in will have a major influence on how the car will perform, as mentioned earlier, the engine is usually the heaviest single piece of the car, and where it's mounted can significantly change the characteristics of the rest of the car, such as how the brakes should be balanced, to how the car accelerates.

• Front Longitudinal: The engine is placed in the front of the car, and the "front" is pointed towards the front of the car with the driveshaft and gearbox trailing back. This engine placement is required to use four wheel drive, and can use front or rear wheel drive. You can usually get the most out of the engine bay in this configuration, and it doesn't intrude much into the driver's cabin. It's also safer to mount the engine in the front, since the engine block will protect the passengers in a front end crash. This also tends to shift the balance of the car forward a bit.
  
• Front Transverse: The engine is still mounted in the front, but instead is rotated 90 degrees, in such a way that the engine is in line with the front axle of the car. This engine configuration is not initially available at the start of a campaign. This is used for front wheel drive, exclusively, until all wheel drive becomes a thing later. This engine doesn't intrude into the passenger cabin space at all, but does restrict overall engine length, depending on the model of car. This setup is also slightly harder to maintain, since the front points towards the side of the car, making the belts harder to access, and in the case of some valve trains (namely Push Rods) the entire engine needs to be removed to replace the camshaft. In the case of V engines, it makes the cam facing the cabin hard to access. It is also exceptionally unusual to use a transverse Boxer too. This sets the entire weight of the engine on the front axle. Available in '62.
  
• Mid Longitudinal: Very few cars can fit a Mid Longitudinal engine. Usually this will only accept a boxer engine in cars where there is a wider mid zone engine bay. This tends to center the balance of the car quite a bit compared to most other engine configurations. It's extremely hard to access the engine however, and this does jack up maintenance cost. This can only be driven in rear wheel drive, until all wheel comes along. Mid engine placement also tends to allow pushrod suspension (once invented) on both axles, which is usually very good for sports cars. A large majority of cars simply can't fit this engine orientation however, even with the tiniest of engines. The screenshot above shows one example of what engine barely fits in a car not specifically designed for a mid engine (in this case, a minimum size I3).
  
• Mid Transverse: Same mount location as a mid, long, but rotated in the same orientation as the axles. This is usually significantly more viable to fit into most cars, but the engines still need to be relatively small. This type of engine is also extremely hard to get to for maintenance, and jacks up maintenance cost significantly. Only supports rear wheel drive. This does offer a small benefit in that you can use the cargo area of the trunk, and bonnet, which can make for some decent utility vehicles when you aren't aiming for a sports car, though this use is unusual, very few cargo oriented bodies allow for a mid engine.
  
• Rear Longitudinal: In this configuration, the engine is mounted in the back of the car, with the front pointed towards the rear, and the gearbox pointed at the driving compartment. This can only be driven rear wheel drive as well until all wheel becomes available. This type of engine is relatively easy to access, compared to a mid mounted engine. Some cars also have a relatively large trunk area, and can fit some very large engines. This tends to shift a lot of the weight of the car to the rear, which can be beneficial, or in some cases, extremely dangerous (I've had a 75-25 balanced car before, it was a deathtrap). Rear engined cars tend to require smaller than usual front tires in order to ensure they don't oversteer, along with generally significantly larger rear tires to hold the weight of the engine. This can inadvertently make rear engine cars rather expensive since tire size almost always must be staggered. One notable advantage to this is that it is specifically used to give the most possible passenger area, and it offers some very good straight line acceleration ability due to the additional grip gained on the rear axle.

The drivetrain is what connects the engine to the wheels, and it's what regulates the engine speeds. There are four core drivetrain designs that you can use, though it's quite likely that most options will be blocked out, depending on the engine placement, which I covered earlier a little bit. The drivetrain also includes the transmission, which is key to making a functional car that can actually accelerate reasonably, which will be covered in the car trim sections. The drivetrain also has a differential, which allows the car to steer without actually bending the crank, and other metal bits that drive the wheels, since the outer wheel has to spin faster in a turn.

• RWD: Rear wheel drive is very common on many cars. The rear axle is the only driver of the car. This gives the car an overall good performance figure all around at pretty much all speeds, and is good for most cars which don't need the extra traction a 4x4 would provide. The typical front engine RWD engine arrangement places the engine in between the drivers compartment and the front axle. This keeps the weight relatively well balanced, but still leans towards the front of the car. If the engine is larger however, this configuration allows the engine to "spill over" the front axle offering the most possible usable space. Almost every single other drivetrain with the engine mounted behind the drivers compartment will have the engine and gearbox pointed towards the rear axle, so a rear RWD will have the transmission pointed at the driver, while a mid engine will point away from them.
  
  
• FWD: Front wheel drive. Pretty much exclusive to front transverse engines, though a front longitudinal can do the job too. It's overall considered to be a poor drivetrain choice, but one that saves money. At lower speed it can be considered to be more drivable than a RWD setup, since the car will more easily "go where you point it". At higher speed, the car will likely start skidding due to understeer since the back wheels are trailing. The typical longitudinal layout places the gearbox just above the axle, with the engine generally seated in front of the axle. This shifts a lot of weight to the front of the car, which makes it very difficult to drive without power steering. This location will also significantly limit engine length, as it effectively eliminates the rear of the engine bay as a viable option. Transverse engines are placed along the axle directly, while this brings the weight balance back a bit, it's still applying a lot of weight to the front axle of the car. Transverse FWD is useful in allowing wide engines in thin engine bays, or long engines in short engine bays. The only major issue which can be run into here, besides cheapness is torque steer, which can happen with extremely powerful engines for their size.
  
  
• 4x4: Common to utility trucks and SUV type cars. The 4x4 arrangement uses a special transfer case near the center of the car to drive both axles at the same speed. This is very good for offroad purposes, but it's also heavy, and as a result siphons off effective power, on top of the added weight. The typical 4x4 engine needs to be set a bit higher than a typical RWD setup to allow for the transfer case to be able to run to the front wheels. The 4x4 is not a full time drivetrain option in Automation, hence, a 4x4 will largely share the same properties as a RWD car.
  
  
• AWD: All wheel drive. With this setup, each wheel or axle is driven individually. This provides the most control over how the car drives, at a relatively high cost to actually engineer and put together. You can fine tune how the car drives itself, and how much power goes to each axle for relative weight. AWD engine placement tends to be shifted forwards slightly, and set higher than most other engines to allow for the extra differentials. AWD can be setup to apply pretty much any configuration, however, unlike a 4x4, there is no choice on where to distribute power. It will always drive in the configuration set. Helical AWD unlocks in 1981. Viscous AWD unlocks in 1985. On-Demand AWD unlocks in 1990. Advanced (computerized) AWD unlocks in 2001. Each type of AWD system operates mostly the same but has a different type of center diff and locking action. Almost all of these options allow you to set a manual power split, except for On-Demand which will act like FWD or RWD depending on if the engine is transverse or not respectively.

All cars have a suspension which attaches the wheels to the rest of the car. The suspension is what separates the entire body of the car from the wheels, and that in turn allows cars to go over bumps in the road without flipping, or twisting the chassis (usually). There are a great deal of suspension systems available, and each performs differently. Different suspension types may also take up engine bay area.

• Solid Axle Leaf: The cheapest (and oldest) of suspension designs. This is a dependent suspension, as a result you cannot camber (tilt in/out) the wheels using this suspension. The wheels are joined together with a solid axle (and usually a differential in between), hence the name and connected to the chassis with layered metal sheets, or leafs. Generally extremely uncomfortable, as the leaves pretty much only hold the axle to the car, but very useful for the weight carrying capacity it offers. This can actually work pretty well for the rear end of a higher capacity cargo vehicle, like a Truck, or SUV, and some family Wagons. Double Leaf can work well for extremely heavy utility Vans and trucks too. Cars using this suspension type up front ride higher than others as a result of the suspension having a rather high minimum height. Decent for going in a straight line, pretty bad otherwise for performance.
  
• Solid Axle Coil: Similar to a leaf suspension, but slightly improved due to the presence of a coiled spring. This suspension is slightly more comfortable than a leaf design, and can still carry a large amount of cargo simultaneously. Quite flexible in terms of ride height when used in the rear, but forces a higher ride when used up front, since the engine has to go above the axle. Many US trucks still use a solid axle coil front combined with a leaf rear when they aren't on wishbones. Not fantastic for performance, but still cheap. When used up front, this generally raises the minimum height significantly, since the engine needs to not hit the axle in the event of a bump. When used on the rear most axle however, it allows for a relatively low car, along with slightly above average gripping ability for RWD cars.
  
• MacPherson Strut: One of the first independent suspensions invented after Double Wishbones, so you can camber the wheels if you wanted for extra tire grip. Less carrying capacity than most other suspensions. Overall a bit more comfortable than the solid axles, and allows for a lower ride height. It is more expensive to produce than solid axles however. A decent choice for city cars. It can also work on cars where you need extra engine bay width. Compared to Double Wishbone suspension, struts don't intrude into the bay at all. Reasonable for performance. Sometimes has issues with camber changes under acceleration, so while independent, it's not perfect for hard driving.
  
• Double Wishbone: One of the most comfortable to use suspensions. This can be mounted in either location of the car, usually without restriction. Double wishbones, being independent suspension allows for stupid amounts of camber to be applied to the wheels, going all the way up to 30 degree camber. A good choice for most non-utility oriented cars, but can even be viable in certain cases on heavier duty vehicles, like Wagons. Double wishbones do intrude into the engine bay slightly, and as a result, they require more space on the sides which can't have engine. That can be particularly important with larger transverse mounts. High quality, and very good for sportier cars due to it's very flexible design. In general a good suspension choice for any market.
  
• Push Rod: A primarily sports car intended suspension available at the start of the '90s as a variant of the Double Wishbone. This cannot be mounted where the engine is, so double pushrod suspensions are only possible on mid engine cars. This suspension cannot carry a car very high off the ground, and it's relatively difficult to make. This suspension has a major advantage of shifting the weight off of the wheels and sides of the car, centering mass, making the car overall better at cornering at the cost of cannibalizing the entire storage space of the area installed.

Rear only suspensions below.

• Semi Trailing Arm: This is an independent suspension. Each arm can pivot accordingly to match the ground driven over, and unlike a live (solid) axle, one tire moving won't affect the other. This is a relatively cheap and well balanced suspension design. It is a decent option for most budget cars.
  
• Torsion Beam: The torsion beam is a semi-independent suspension type that can only be used on front wheel drive cars. It cannot be used with any other type of drivetrain. It's overall a fairly good all round suspension when compared to a solid axle, but pails in comparison to double wishbone, or even a semi trailing arm. This type of suspension actually relies on the suspension itself twisting the central arm when going over a bump. This keeps the rear tires on the ground, and only works when not powered. A decent choice for a budget car which needs tire camber as well as cargo capacity.
  
• Multilink: An advanced suspension type, available only at the start of the '90s. Better all around than a double wishbone for passenger comfort and racing sportiness at the cost of a more difficult to engineer and assemble system, since there are so many more parts to go with it. The suspension in game is just one of many hundreds of possible configurations that this suspension can be designed as.

As with the car itself, the engine also has different stats that heavily influence the car itself.

• Performance Index: This is a stat that shows how much usable power you have. Going too far beyond the peak power of the engine will reduce this, as the power at that point can't really be used. This stat has actually very little bearing on what makes an engine appeal to certain markets.
  
• Weight: This shows how heavy the engine is. A heavier engine needs to push itself, along with the rest of the car, so while a heavy engine generally delivers more power, this is usually slightly offset by the mass of the engine itself.
  
• Reliability: This is how reliable your engine is. A good reliability score changes over the years, trending towards more reliable over time for the same tech being used.
  
• Throttle Response: This is how quickly your engine reacts to changes in the throttle (the accelerator pedal). A higher value is generally better for sporty trims, with lower generally better for luxury trims, and a middle ground good for anyone else.
  
• Smoothness: This is how smooth and comfortable your engine is in terms of physical movement/shake in the bay. A higher value means your car will be more comfortable. A smoother engine will also be more reliable as it's not physically rattling itself apart.
  
• Loudness: This is how loud your engine is. A louder engine will be sportier, but less comfortable, up to a certain point, where the loudness actually hampers sportiness slightly.
  
• Required Cooling: This is how much much cooling/airflow your engine needs to stay reliable. This is important, an engine which needs more airflow will cause more aerodynamic drag.
  
• Service Costs: This is how expensive your engine is to maintain. Higher costs will make budget buyers less likely to buy your car, as they cannot afford to maintain it.
  
• Fuel Efficiency: This is how fuel efficient your engine is in the RPM range of around 1500 RPM to 2500 RPM at about 40% to 80% throttle. This is measuring the average thermal efficiency of the fuel in the range. While it's a good ruler to see how efficient the engine is. This will have little bearing depending on what the engine is installed in, in regards to final fuel economy of the completed car.
  
• Octane: This is your engine’s octane, measured in either RON or AKI. Octane is a measure of how effectively you are using the fuel, as well as how resistant the fuel is to knocking. If you exceed the octane rating, the fuel will ignite prematurely, causing a "knock". The game counteracts knock by pulling ignition timing to prevent this preignition.
  
• Emissions: This is how harming to the environment your engine is rated against the WES standards. This will only work with the engine installed in a completed car.
  
• Material Costs: This is how much it costs in total to get the materials to build your engine before markup for sale.
  
• Production Units (PU): This is how many man hours it takes to produce your engine. Lower numbers here mean faster production times, and as a result, lower prices, as worker wage is a concern in how much you need to mark up the engine to break even.
  
• Engineering Time (ET): This is how many months it will take to engineer your engine. This will be important in the light campaign. A lower engineering time will mean your engine and by extension car will be engineered quicker and can be sold sooner. Engineering time can be brought down with familiarity of what you're working with, such as if your car company has built an Inline 4 engine since the early '50s, and you're now in the late '60s building a different family of I4s.

As mentioned, repeatedly throughout this guide, the engine block is the core of the car, in multiple ways. Choosing the block is something that should be considered heavily each time you build a car, since each different block type has various benefits, and weaknesses. The block and heads cannot be changed, but the other components that connect to them can be changed per family to create variants of the same engine family.

Inline engines are relatively simple. Each piston is arranged in a line. This keeps the engines relatively cheap, but makes them comparatively much longer as more pistons are added. Inline engines generally take up very little space in an engine bay otherwise, since they tend to leave a lot of space off to their sides. Inline engines are quite common engines, and generally have easier access than other engine types.

V engines are generally used to save space in the engine bay while also still allowing for extra cylinders. Variants with lower numbers of pistons tend to be relatively less smooth than versions with more pistons. They are also generally a bit more complex than comparative piston count Inline engines. Their compactness makes them viable on quite a lot of cars, presuming they aren't higher count piston engines.

Also known as Flat engines. Boxer engines are, in fact, flat, with pistons set across from each other at a full 180 degree angle. Boxers specifically have opposed action pistons, so the pistons matching the same cylinder will both be out, and in simultaneously. These engines are wide, in order to save on height, and as a result keep the center of gravity on the car lower. Boxers tend to be difficult to work around due to their width, and usually end up a bit more expensive than other configurations in most cases due to engineering the fit.

Due to laziness i'm combining these together. They basically do the same thing, fancier stuff is lighter.

• Cast Iron: Very heavy, very cheap, available from the beginning of the game. Requires an Iron Foundry to use, but such a foundry is also the cheapest of all three foundries.
  
• Aluminium: A lighter alternative to straight iron. This is more expensive and complex to manufacture, but the extra mass saved can make the difference in performance cars. Requires Aluminum Foundries to use. Aluminum blocks and heads will generally need to have iron cylinder liners to keep the aluminum from cracking. This makes them a good deal more complicated than Iron or AlSi engine components. Available as a head option in the '50s and as a block option in the '60s. There are 2 types of aluminum blocks, heavy or light. Heavier aluminum is still lighter than cast iron and provides decent emissions benefit, while light aluminum is relatively weak, but is quite light.
  
• AlSi: Aluminum silica alloy. Available in '96 and can be produced out of Aluminum Foundries. A bit more complex and expensive to manufacture, but easier to engineer for, since, unlike Aluminium, AlSi doesn't need iron inserts in the piston chamber. AlSi engines can be built heavy or light like aluminum blocks, but AlSi is a bit more frail than aluminum blocks while offering even lighter mass and even better emissions characteristics.
  
• Aluminum Billet: Available in the late 90s, a billet block is a solid block of milled aluminum intended usually to be used as a low volume racing block. Quite light and durable, but extremely expensive and slow to assemble, and requires C&C machinery to actually make.
  
• Magnesium: Only available after '05, a magnesium block (and only block) is extremely expensive, and extremely light. Generally, it will only be used in supercars. Magnesium likes to react with basically everything so, as a result this type of block is massively labor intensive and difficult to engineer. This block requires the particularly expensive Magnesium Works factory add-on.

• Inline 3: The Inline 3 is a budget engine. Without forced induction via a turbocharger, or a very aggressive cam profile this engine is not capable of outputting very much power. When sized over one liter, or 1000 cc or 61 ci, the engine tends to rattle violently and that often tanks the reliability of the engine and comfort to drive the car mounting it unless a lot of quality is put into the bottom end. They'll also usually come apart completely if sized over 2000 cc or 122 ci, even with 2020 tech and quality spam. Due to the small size of these types of engines, it is feasible to use just single barrel carburetors and single point fuel injection, making the engine even cheaper. It does tend to work for cars where high power isn't required, such as City cars, and smaller Family cars. This engine is also pretty much the best economy engine due to the lack of so many components compared to other engines, which in turn reduces friction to slow the engine down. It will be obvious to buyers that you're trying to be cheap though, and this engine is usually very bad for prestiege.
  
• Inline 4: A slightly higher cost budget engine, with four cylinders instead of just three. This is a very common engine throught history, with a higher fuel displacement than an I3, due to the extra cylinder, assuming the bore and stroke are the same. As a result of this higher displacement, and extra cylinder, you can get this engine up to around 3L, 3000 cc or 183 ci before you start to run into some issues with the bottom end. Each piston is run in pairs, and as a result the engine still isn't very smooth since all pistons point up. A good choice for most cars which aren't trying to be fancy, and aim to keep costs low.
  
• Inline 5: Available starting in 1970. The Inline 5 is overall a relatively smooth, and slightly premium(ish) engine. This engine is noticeably long, and may have some trouble fitting into smaller engine bays. More displacement means higher power however, and this engine can be made fairly massive without running into significant smoothness issues. A good mid range engine for larger cars.
  
• Inline 6: One of the longest engines in the game, short of the DLC V16. This engine is inherently smooth, as it essentially links together two I3 engines, and runs the pistons on opposite ends of each other at the same time, such as both outside pistons, both "middle" pistons, and then both of the inner pistons. This reduces any shake that would normally be present on other engine types, even at a high CC. Due to this smoothness, and overall larger size, this makes a very good engine for premium cars, such as convertibles, and other larger models while still being reasonably priced. The hard part is getting it to actually fit into the engine bay.

• V6: Essentially two I3 blocks stuck together onto a single crankshaft. This engine doesn't become available until the '60s. This engine has the displacement of an I6 in the length package of an I3 engine at the cost of some height, and the added complexity of needing two separate camshafts. You usually get some weight savings versus an I6. This block type also gets a small advantage in using smaller types of fuel intakes, as the pistons and valves are closer to the intake compared to an inline engine. This engine also tends to not run very smoothly, even when compared to an Inline 4. It's a good alternative to the I6 when you need to save space, and a bit of mass, and has many practical applications in many car types.
  
• V8: Similar to the V6, but with an additional cylinder per side. The V8 is the bigger brother of the V6, and offers more smoothness, and power compared to other engines of their relative displacement. They are very practical, if expensive engines, which can be used in a variety of cars. It generally is preferable to use a 90 degree V8 however if smoothness and reliability are priority. This engine also only becomes available in the '60s, as 90 degree V8's are more natural to run, and don't require special firing orders and balancing shafts. However, some manufacturers may still wish to work with a familiar bank angle and choose to go with a 60 degree V8, usually if they've produced V12's or V6's in the past.
  
• V12: Two I6 blocks combined. This engine is incredibly smooth to run, and is also usually incredibly expensive to tool, engineer for, and produce. However, they make for fantastic luxury, and sport/supercar engines. This is the highest scoring engine for prestiege that you can get without purchasing the V16 DLC, as well as the longest engine. In very many cases, a V12 is more than sufficient to get the job done when compared to a V16.

• V6: Similar to the 60 degree V6, but instead of a 60 degree angle, the pistons are aligned at a 90 degree angle from each other. This creates a very similar performing engine to the 60 degree alternative, at the cost of smoothness, and often some reliability in the engine. You will save space vertically at the cost of extra width, and more fill factor. The 90 degree V6 is not as naturally balanced as the 60 degree version, but may make engineering cheaper for companies which have routinely produced 90 degree engines, such as a V8 (which was relatively common on sports cars). This becomes available at the same time as the 60 degree V6 as well.
  
• V8: The 90 degree V8 is in many ways similar to it's 60 degree variant. However, due to it's design, it can have two crank configurations. The first is "crossplane" (or the normal crank) where the crank has an arm at a 90 degree angle from the next arm. This is generally smooth, and leads to an "American" style V8 generally, with a bit of a "grumbly" engine sound for lack of a better term since the firing order is more staggered. The other crank is a "flatplane" where the crank has the arm alternating a full 180 degrees, and is essentially two Inline 4 engines on the crank. Flatplanes are more common to European V8s and have their own specific, more "angry" tone. A flatplane is generally more efficient with it's exhaust, and can deliver slightly more mid range power (3k to 5k RPM) per cycle with a single exhaust as a result (they also sound terrifying with race intakes and straight pipe exhaust at high RPM too).
  
• V10: A middle ground between the V8 and V12 which isn't available until '85. It's a pretty prestigious and large engine, and it's a good choice for luxury cars, as well as high end trucks. It has an extremely distinct sound to it as well.
  
• V16 (DLC): For when you want the absolute most out of the car. The V16 is stupidly expensive in terms of materials and engineering. It's extremely prestigious, being one of the smoothest engines available, as well as having the highest piston count. The V16 is basically always restricted to high end sports and luxury cars, as a result of it's usually massive cost, and the sheer amount of power they are capable of producing.

• Boxer 4: Boxer engines are pretty unique compared to most of the other engines noted above. Both sets of pistons are set across from each other and connect to a single crank. This makes for a very wide, very short engine. The Boxer 4 has four pistons, obviously, and it has a much lower center of mass, making it a good choice for sports cars. The Boxer 4 is also generally smoother than a same size Inline 4. Boxers tend to have trouble with single intake systems, since the pistons on each side are set so far apart from each other. The Boxer 4 can fit into nearly every car in the game in the Mid engine compartment longitudinally, if made small enough as they are the length of an Inline 2 (which isn't a thing in Automation).
  
• Boxer 6: Similar to the Boxer 4, with 6 pistons, clearly. The Boxer 6 is smoother than the Boxer 4 by a small margin, and has higher displacement. It can serve in place of a V6 engine in many cars where height may be an issue, and width isn't, such as low bonnet sports cars.

Nearly all of the heads are available at the start of the game, they play a major role on how well the engine will perform, and at which point you might run into valve float (the point in which the valve doesn't snap shut completely due to high engine RPM). All configurations shown here are two valve per cylinder on an Inline 4.

• Push Rods (OHV): This valve system has a single camshaft mounted inside the engine block itself regardless of configuration which handles all of the valves by pushing a rocker with rods, hence pushrod, the valves above the pistons are sealed inside the block as well. It's one of the cheapest types of head assembly, but it tends to have major issues with higher RPM engines since there are so many parts that handle the valves. As a result this type of head is usually best used in cars where high RPM isn't necessarily required, such as trucks, and some city cars. Due to the way it works, it can't be used with any of the fancier variable valve techs either. This valve system is extremely compact, and can allow for some large engines without eating into engine bay space too much.
  
• Direct Acting Overhead Cam (OHC): Unlike a push rod head, the camshaft is located above the pistons, where it has it's two valves placed directly over each piston. This allows for less friction in the system, allowing for higher RPM. When compared to a standard two valve Overhead Cam, this valve system is slightly more resistant to valve float since there is no reciprocating mass due to the rockers. This valve system is incredibly simple, and cheap to a degree. Direct Acting is the second smallest valve system available, though it will take up more forwards space than a pushrod due to extra belts.
  
• Overhead Cam (SOHC): This head is similar to a direct acting cam, but the valves are offset to allow for smoother flow of fuel, and exhaust, in, and out of the system. Since it's valves are not placed directly over the piston, it also allows for higher fuel efficiency due to cleaner spark ignition, and better fuel distribution. There is also the option to mount additional valves using this setup, which further increases efficiency as the flow is greater, and distribution is more even. Single Overhead Cam is larger than a direct acting since there's more space required to use the rockers and additional valves.
  
• Dual Ovehread Cam (DOHC): Unlike the other head setups, this valve system uses two separate camshafts, one to actuate the intake, and one to actuate the exhaust. This allows for significantly less friction on each cam allowing for further high RPM. It also more naturally allows for additional valves to be used, as well as smoother airflow. Dual Overhead Cam is the largest of valve-trains, and can take up a lot of engine bay area due to the fact that each bank will have two offset cams, plus larger belt assemblies to run both cams.

All of the heads above can be designed with a specific focus for the car being built. Aluminum heads unlock in the year 1950, are generally more efficient than Iron heads, but tend to be very unreliable until the 70s. Eco heads unlock in the year 1963 by default and shift the engine head design to offer better power at low RPM but make the top end more susceptible to valve float. Standard designs are "normal" and are the cheapest to design. Performance heads tend to reduce low end performance in favor of allowing higher revs. Lastly, the racing billet head unlocks by default in 1993, and is designed for peak high end performance at very high manufacturing cost.

The bottom end refers to the crankshaft, the conrod (connecting rod) and the piston itself. The bottom end can be made of various materials, and depending on the forces created by the engine, will require different components to keep the parts from breaking. Most components will also produce different results in terms of fuel efficiency, or engine smoothness.

• Cast Iron: The initial crank type. It's overall relatively heavy compared to the other components, but the crank is usually the most solid piece of the engine for torque loading and RPM. The cast crank is the weakest type of crank, while also the cheapest. Comes as standard or heavy duty depending on if you want speed or torque tolerance.
  
• Forged: A forged crank is quite a bit tougher than a cast iron crank, as well as notably lighter. There is a rather high startup cost to use forged components however, since the engine factory needs to have a Forge Works add-on. Immediately available. Has a light, standard and heavy variants.
  
• Billet Steel: The highest grade crank. Made from milling a solid block of steel, instead of being pressed out of a forge or cast. This requires a C&C shop to fine tune the cranks being produced. They are the lightest, and toughest crank available, but not available until much later in the game. This supports a very high RPM and torque amount. Available starting in '86.

• Light Cast: Lightweight cast controds designed to be relatively light, but in general are pretty weak.
  
• Cast: A "standard" cast conrod to connect the piston to the crank. Cheap and relatively weak, but works in most engines.
  
• Heavy Duty Cast: A more solid, and heavy conrod designed to handle rotational speeds and torque better, but tends to strain the crankshaft due to the added mass.
  
• Heavy Duty Forged: A flat H shaped piece of forged steel serves as the conrod. This is overall better in many statistics than cast components, and serves as an actually lighter alternative to the standard cast conrod. Available in '56.
  
• Lightweight Forged: A lighter version of the forged conrod, as a result it can take fewer stresses, but are just about as good as a heavy duty cast at handling torque. Available in '67.
  
• Titanium: The strongest conrod available, that comes with an immense price tag due to the rarity of titanium itself. In cars where cost is no object, these conrods allow for the highest possible of RPM speeds. They do require a C&C shop to produce however. Available in '97.

• Light Cast: A light variant of the standard piston. Usually used to gain some potential engine RPM but won't be able to handle much engine power overall.
  
• Cast: A simple cast iron or aluminum piston to provide compression to the engine. Very cheap, and not good at handling most types of stress.
  
• Heavy Duty Cast: A more densely cast piston ensuring that the piston won't shatter under high torque load. This does come at the cost of the piston not being able to handle high speed stress, and is very bad in most somewhat high RPM engines.
  
• Forged: A forged aluminum piston, ensuring better overall performance when compared to cast pistons, able to take substantially more stress from torque, and speed. Forged pistons also reduce octane in game as an abstraction that it's less likely for heat to gather in a "bubble" just above the piston, since the process makes a smoother surface. Available in '56.
  
• Hypereutectic Cast: A cast piston made of an aluminum alloy (usually) with a special process in that the components are just barely melted before being cast into shape. These types of pistons are a bit tougher than the standard cast pistons for taking torque, and they help a bit to reduce fuel emissions since they come out a bit harder, and more resistant to expansion which leads to less oil burn/blowby. Also helps to run the engine a bit quieter. An option starting in the '70s.
  
• Low Friction Cast: A lower friction and weight variant of the standard cast pistons. This harms the stresses the piston can take, making them more sensitive than just standard casts. However, it does make the engine slightly more fuel efficient, due to reducing the friction all around and as a result wastes less energy. Available in '91.
  
• Lightweight Forged: A lighter variant of the standard forged piston. This piston type can take immense amounts of RPM stress, and is especially useful for sports cars where high engine RPM is required. Available in '91.

Almost every engine type in Automation now as of 4.2 comes with a balancing mass selection. None is nothing being added to keep the crank from tearing itself apart, but offers the highest response when going for sporty engines. A majority of engines should at minimum run a harmonic damper, which is effectively a counterweight added to the end of the crankshaft to reduce the impact of rotating a large screw effectively at one end. Some more unbalanced engine configurations, like the I3, I4, and imbalanced V6/V8s can have balance shafts, which are extra accessory parts added to the engine with counterweights to counter natural imbalances caused by the engine configuration. Balance shafts are particularly heavy and will sap off engine efficiency, especially at high loads.

You can set a specific variant size to be below the size of the base family model. Usually you'd want to do this to de-tune an engine you've already made. For example, creating a debored variant of one engine to remain tax compliant for a smaller city car, and another variant with upbored pistons, and destroked to fit into a sports car where taxes are less of an important factor over pure performance.

The top end refers to the valves of the engine, and the camshaft which regulates the valves themselves. This section is where you determine who the engine is actually going to sell to, and how the engine is intended to perform, as it has major influences on the fuel economy of the car/engine, and it almost single handedley shapes the torque/power curve of the engine. Also, sliders!

Compression: The compression ratio is what determines how far up the shaft the piston will travel. High compression ratios make for overall better power and efficiency, as the fuel is detonating in a smaller space, giving more power overall for the same amount of fuel in the chamber. Setting the compression too high however will cause knocking due to the heat of the compression, severely reducing efficiency of each cycle as well as potentially damaging the engine. This results in the game pulling your ignition timing to compensate.

Cam Profile: The cam profile largely dictates how the engine will be run. The cam dictates how much fuel/air gets into the engine for each cycle, as well as how long the exhaust is held open for. The cam profile is what determines how large the lobes on the camshaft are in regards to how long to hold the valves open (among other things like spring stiffness). A lower profile generally means higher low end power and fuel efficiency which is suitable for most family and utility purposes since less fuel is burned. Low cam profiles do generally increase knock chance since smaller amounts of fuel burn hotter than a more densely filled area. A higher cam profile tends to turn the engine into a high power focused engine, with a delayed torque curve peak, and is generally suited to cars where high RPM power is preferable over fuel economy and general engine smoothness, since it sucks in more fuel and blows out more air (sometimes simultaneously, which is why fuel economy goes down). High cams work well with high compression engines since the camming adds a lot of fuel per cycle which keeps the temperature relatively low compared to a lean burn. You generally tweak the cam profile to push the torque peak to one end or the other, where a high profile makes a peak at high RPM, and a low profile moves that peak to lower RPM. The effects of cam profile are heavily dependent on the head design, where a high cam eco head will have a harder time gaining torque at the high end, benefiting from low cams, while a performance/race head will be the inverse both ways.

Spring Stiffness: The second core component of a valvetrain. The springs attached to the valves is what will partially determine the peak engine power point. Higher spring stiffness makes the engine slightly louder, and will generally push the peak the engine can operate at higher, provided the intake and exhaust permit it. This comes at the cost of overall engine reliability slightly, as well as broad base loss of efficiency and overall power below peak RPM. Softer springs are beneficial for a quieter, slightly more reliable, and slightly more overall efficient engine. Reducing spring stiffness can also be used to induce an "artificial" power limit onto the engine by inducing safe valve float, creating a decrease in power past the RPM point at which the springs will allow the engine to operate. Setting the springs too soft will induce valve float, which can damage the engine due to the valves contacting the pistons, or fuel/exhaust backflow the wrong direction. Spring stiffness is closely tied to the overall engine RPM and should usually be tuned simultaneously.

VVT: Variable Valve Timing allows for an adjustment to be done on when the valve opens and closes in the engine in accordance with engine speed. This is done through various means. Practically, this improves power across the entirety of the band, as well as fuel economy, and fuel emissions. You will especially notice the effects of VVT on very aggressively cammed engines, there will usually be a noticeable "dip" before the car "jumps on the cam" and actually increases in torque noticeably. With VVT, especially DOHC VVT on each cam, you should notice that the low end power is significantly higher, and there will be less of a bump in power, leading to a smoother, but still near vertical torque curve.

VVL: Variable Valve Lift, sometimes referred to as VTEC by players since this is the Honda VTEC technology, allows you to set 2 cam profiles. Additionally CVVL is a similar technology which is designed on optimizing fuel economy by continuously adjusting valve lift at the cost of inducing valve float at higher revs typically.

VVL Profile: If you have installed VVL into the engine, this is where you'd set your second cam profile for the engine, which allows for hybrid function engines depending on where the engine is in their specified RPM range for each profile.

Turbochargers available for use in Automation. They become available in '75, and they effectively boost the power of the engine by applying extra pressure into the engine versus a naturally aspirated engine, which sucks air into the engine naturally through the intake (obviously).

Naturally aspirated engines tend to have rather "normal" power curves, for lack of a better term. They'll gradually go up in power as the throttle is depressed, and they usually handle fairly well in most RPM ranges when compared to using a turbo.

Turbochargers on the other hand use a compressor and turbine, powered by the exhaust of the engine to suck extra air into the intake, "boosting" the engine by adding extra pressurization to the piston chamber. They can be setup to provide boost at almost any range of the torque band. Generally smaller turbos work best to provide increased fuel efficiency at low RPM, since a smaller turbo is easier to spool up, but provides less boost. A large turbo can provide massive boosts to torque, once they spool up completely. This can create torque "mountains", which while not necessarily easy, nor fun to drive lead to massive boosts in power at the peak of the boost.

Turbos, while they will work with Carburetors, generally should not be used with them if it can be avoided. Turbochargers add pressure which carburetors typically aren't designed to handle, which means you have to design the engine and carburetor around either running on boost, or off boost, or some weird compromise between both which kinda just makes the engine run bad.

Lastly, turbochargers as a result of how they work can also reduce the noise of the engine/exhaust, since the turbo spinning reduces the overall speed of the exhaust once it leaves the piston chamber.

Superchargers were added in the Al Rima update, and function similarly to turbochargers, but instead use a belt to spin the compressor, of which Automation allows for 3 designs, with various options. Roots and centrifugal superchargers are available at the start of the game with the screw type supercharger unlocking in 1970 by default.

Turbochargers have changed significantly since their implementation, and are now quite a bit more complex, but also quite a lot more flexible in their application, especially on modern cars.

Your turbo has two key parts, the turbo, and the compressor. Automation provides you a tool to work with the compressor on your engine, via the compressor map graph.

Note the shaded area on the graph and the color grading going on within the map. This shows your approximate efficiency for the turbo you've applied to the engine as the engine revs up at maximum throttle. The blue line within the map is the amount of air the compressor is able to feed into the engine, with the left/right axis the overall amount of air going through the system, and the up/down axis the effective pressure built up by the compressor that is fed into the engine.

The darkened area indicates where the compressor will fail due to various factors. Going too close to the left of the compressor map will induce what is known as surge, where the compressor builds up more pressure than the engine can accept, causing airflow to reverse back into the compressor. This can cause the bearing on the turbo to break, as you'll have pressure on both ends effectively trying to rotate the turbo both ways at once. Falling off the right of the map will usually do two things, build heat, and mechanical stress as the turbine spins faster than the parts can handle. This will cause the intake charge and the exhaust to heat up dramatically, and potentially warp the turbine blades. Falling off the top of the map will cause the compressor to fail due to excessive boost pressure, usually exploding in the process.

You can adjust your turbo in multiple ways, but the major thing to pay attention to are the four turbo tune sliders, which affect the size, trim, and boost limit of your turbo.
The compressor as mentioned affects the overall size of the compressor map and bigger compressors make it easier for high revving, or high capacity engines to keep their boost within the compressor map, but will be harder to spool.
The turbine is what accepts the exhaust gas of the engine to spool the compressor. The turbine can be set to various sizes depending on the application of the engine, with smaller turbines allowing you to spool the whole turbo faster, but will induce choke which will effectively cap the amount of torque the engine can create since the engine expends energy forcing the exhaust gas out through the turbine. Making the turbine larger usually costs effective spool time, but may also be necessary to dodge surge issues, or for uncorking the engine to gain more effective power at the cost of a later spool.

The trim slider affects the design of the compressor and turbine blades to shape the compressor map for different targets. A lower trim will usually create a smaller ultimate boost cap, but help you to spool sooner, while a higher trim will push the entire compressor map right, making the turbo more susceptible to surge issues, and spool later, but generally operate better on higher RPM or capacity engines, and deliver better power.
Lastly there is the wastegate slider which will determine at what point you want to release the boost pressure to sustain the current level of air going into the engine. Higher boost turbos are usually harder to work with as they tend to have much hotter intake charges but offer more torque, while low boost turbos are the opposite. This decision is usually a trade of fuel economy versus overall power at the end as injecting more air means more fuel needs to go into the engine too or it'll rapidly heat up. See part 2 of the fuel system section for more information on the implications of this.

Lastly, I'll describe the techs you can add to turbos to make them work in your favor.

Wastegate is a mechanical spring operated wastegate. It's the most basic gate, but will "leak" boost as you approach the intended cap usually, causing later spool than with more advanced tech.
Boost Control is a solenoid based wastegate that uses a sensor to read effective air pressure in the intake, which will cause the solenoid to open the wastegate when pressure release is requested, and close the gate when more pressure is desired.
Smart Boost is an advanced turbo tech that ensures that the wastegate is open when the turbo is within range of surge stress to alleviate the risks of using a "surgey" turbo, while also getting the best boost pressure pre-spool.

Standard Geomerty turbos are your typical standard turbos with a single exhaust intake leading into the inducer.
Twin Scroll turbines are special turbines that divide the exhaust charges into two separate vanes to build better effective pressure inside the turbine which will help gain a faster spool of the turbo. These can only be used on even count cylinder banks however.
Variable Geometry is an advanced turbo with special fins built into the turbine which allows for two effective trims on the turbo that swap as more pressure is built. These are extremely expensive and rare on gas cars though

Journal Bearings are the standard bearing on most turbos. They're quiet but not as responsive as Ball Bearings, which are louder but offer a better "feel" as they react to the throttle input faster for the monetary cost of having the ball bearings added.

Superchargers generally follow a similar format to turbochargers, except that they operate off of the crankshaft instead of the exhaust of the engine. This allows them to deliver immediate boost, but runs the risk of killing off low end power very harshly if tuned incorrectly. Superchargers in general tend to be rare on cars, even to this day, but they are points of prestiege. Their economy and impact on emissions tends to be extremely bad making them not viable for more common markets, though there are some exceptions and using them in game to bypass capacity taxes can be viable in some markets. They are usually a major point of interest for higher end markets due to the novelty and funny noises.

Roots and screw superchargers tend to have a low maximum pressure ratio compared to centrifugal superchargers, but typically have desirable driving characteristics due to the fact that they don't escalate power as rapidly. The key difference between the roots and a screw supercharger is that roots superchargers tend to use rotors, while screw type chargers use a screw threading to gather and force extra air into the engine. Screw superchargers as a result tend to be more efficient overall due to their design but harder to pump at lower engine speeds.

Centrifugal superchargers are effectively turbochargers in every practical way except for not relying on exhaust using a turbine, being geared to the crank instead. Centrifugal designs are a good way to get a lot of power very early into the game but due to the way they need to be geared tend to massively hamper low end performance. The centrifugal charger will share the same compressor map of an equivalent size turbocharger.

Supercharger size will determine how much air the supercharger is capable of compressing in a given revolution. Larger superchargers deliver more boost sooner, but induce more friction and are heavier. Smaller superchargers deliver less boost in general unless geared to spin faster and are usually less tolerant of more boost pressure.
Supercharger gear ratio sets the ratio of how fast the supercharger rotates relative to the crankshaft, so a 2.00 ratio would mean the supercharger spins at 6k RPM when the engine is spinning at 3k RPM, a higher gear ratio generally allows for more pressure buildup but can run the risk of mechanical strain if the compressor is pushed too far off the top or right of the map.
Supercharger trim works quite similarly to how turbocharger trim settings work, but generally unless the turbo is centrifugal, more trim generally does not increase boost capacity, but instead moves around the supercharger efficiency to higher/farther down the compressor map. Higher trim superchargers are normally optimized to deliver the coldest most efficient intake charge near peak engine RPM, if tuned properly. Lower trims move the efficiency down into lower speeds which improves low range performance, but generally delivers high pressure boost less efficiently at peak RPM.

Superchargers can have an option called a bypass. Of which there are 4 options, mainly used to allow for more optimal cruising applications by disconnecting the supercharger in one way or another.
None doesn't use a bypass at all, so the supercharger is always forcing boost.
Bypass adds a release valve somewhere in the intake that allows the extra pressure to be released at low throttle at values below 50%. This still has the supercharger spinning, but does not apply low end boost and it helps conserve fuel.
Clutch bypass adds a clutch to the supercharger belt which disconnects the supercharger in low throttle applications, as well as allows the supercharger to shut off when it is running the risk of mechanical damage.
Advanced bypasses work similarly to turbochargers by allowing you to add a set maximum pressure limit to the supercharger, and opens a wastegate when pressure gets too high. This allows for an extremely responsive and short geared supercharger without running the risk of blowing it up due to pressure.

The fuel system itself is how the engine actually gets it's air and fuel mixture in order to run the ignition cycles. There are two major types of fuel system, carburetors, and injection, each with multiple variants and configurations.

Carburetors work on a fairly simple principle of when the engine is running, the carburetor sucks in air against the fuel lines, similar to using a can of compressed air along the top edge a straw in a cup of water, also known as the Venturi effect. Since engines create a vacuum once the exhaust is vented out of the piston chamber, this creates pressure, which then tries to pull air into the intake fuel valve. The carburetor comes into play by restricting airflow with a throttle plate, and uses that high pressure airflow to add fuel into the mixture, letting the engine run. For better efficiency, and control of the fuel mix, some carbs have multiple "barrels" which can separately throttle their air intakes. For larger engines, some systems will require additional carburetors as well, since only so much air can get through the pipe(s) at once, plus your typical carburetor generally will have trouble getting the air/fuel mixture from itself to very distant intakes without losing some of the fuel along the intake due to condensation. More complex carbeurators have a wider fuel mix ratio range than simpler carbeurators which will come into play as emissions are more of a concern.

• Single Barrel: An extremely simple carb setup. A single pipe, with a single barrel and throttle plate. It works well enough for smaller engines. It's cheap to make, but relatively inefficient. You typically will want, but not need extra single barrels on anything bigger than an I4 if shooting for performance. This tends to be the most reliable fuel system as well due to it's simplicity.
  
• Single Barrel Eco: Pretty much the same as a single barrel carb, but with a control piston built into the carb. This creates a higher air pressure compared to a normal single barrel carb at all speeds, but tends to constrict the carb(s) at high flow. It is very economical for fuel use compared to a standard single barrel if you can get past the part where it's probably strangling the engine a bit. It's also one of the more emissions compliant carbeurators when emissions standards start coming along.
  
• 2 Barrel: A single intake with a second barrel to regulate airflow better, as only one plate is open, unless the throttle demands the second plate to be open as well. As a result it can manipulate a larger range fuel mix when compared to a single barrel, and it generally delivers more power too. A bit more complex, and can reduce reliability slightly. Available in '48.
  
• DCOE: Basically two single barrel carbs straight piped into the piston chamber, unlike other variants where the air needs to make a turn to get into the intake valves. This makes them much more fuel inefficient across the board, but generally allows for higher power due to less air restriction even compared to a four barrel carb. Available in '54. Alternative real world names for this system include Webber, or Sidedraft Carb.
  
• 4 Barrel: A carb with four independent throttle plates. This is a high quality version of the carburetor, since it has significantly more control over how much air/fuel gets into the engine. It is rather complicated to manufacture and maintain for a carb though. Available in '59.

Fuel injection, unlike the carburetor, actually directly injects fuel into the intake or cylinder of the engine with a pump. Fuel injection is almost always more economical and provides more power than using a carburetor, but it is also vastly more complex to actually produce engines using injection, since the process usually involves sensors and instruments not usually used in a carbureted engine. Systems with multiple configuration options will allow for separate air intake throttles, but will still inject fuel per cylinder in most cases (except for single point EFI). Injection based fuel systems allow you to tune the engine with a Lambda 1 range, which is essential for later emissions standards. Read the emissions section for more information.

• Mechanical Fuel Injection: The first iteration of fuel injection available in '64. This system uses mechanical sensors and timing to inject the fuel into either the intake valve itself, or directly inject into each cylinder. This typically used a high pressure fuel rail and pumps. This method is generally overall better than using most carbs for a lot of power and emissions compliance, but is also much more expensive in terms of cost, and engineering time. As a result, it's generally only suited for early high end racing engines. It also tends to be incredibly unreliable without substantial quality investment.
  
• Single Point Electronic Fuel Injection: The first electronically monitored fuel injection system available in '78. This system is generally better than a four barrel setup. It is required to use any stability controls that have been created that aren't simple ABS. However, it struggles with longer engines, since as one would guess, the fuel is injected at a single point at the air intake. It's essentially a four barrel carburetor that has an ECU controlling the fuel addition instead of being totally dependent on airflow. This in effect can actually make this fuel system somewhat less effective than having multiple seperate carbeurators particularly on longer engines.
  
• Multi Point Electronic Fuel Injection: Starting in '82, multiple point fuel injection comes along. This is an electronically monitored fuel injection system, which can be configured to run in a single, twin (in the case of V engines) and per cylinder throttled fuel injection. This fuel system injects into the intake valve region of each piston instead of the intake of the engine, regardless of configuration. A very efficient fuel system, and offers a lot of power if setup for that purpose, while also able to be configured for low power economy work.
  
• Direct Injection: Instead of injecting into the intake of the piston chamber, direct injection directly injects the fuel into the cylinders of the engine. This provides vastly more power and fuel efficiency at a much higher cost. This only becomes available in '01 however. This fuel system is relatively finicky, and requires more constant maintenance than a standard multipoint fuel system.

Due to character limits, this category has been split in two.

All fuel systems require an intake in order to get the air actually into the engine. What type of intake you use will have a large influence on the loudness of the engine, how much it costs to maintain, overall performance, and overall engine reliability.

• Compact: The most basic and simple intake runner designed for basic function on an engine, and that's it. Usually will hamper performance on the engine, but it's dirt cheap to engineer and attach to an engine, and is the most reliable choice.
  
• Standard Low: An intake with long, thin intake runners designed to optimize low range airflow for better low RPM economy (pretty much idle to ~3k revs). Usually for engines where cruising economy is a focus of the car.
  
• Standard Mid: A standard intake airbox with slightly shorter, wider intake runners designed to optimize airflow from around 3k revs to 5.5k revs. A decent choice on more performance oriented cars without excessive maintenance costs or noise.
  
• Variable: A complex intake manifold only available for multipoint and direct injected engines. It's effectively two types of intake runners with valves to seperate the two modes of the intake. This will fill in the gap between standard mid and a bit below performance high. Very costly and unreliable, but makes for a very wide performance range and can be tuned quite a bit.
  
• Performance Mid: A step above standard mid intakes, but starts to expose intake resonances, making this intake highly tunable for peak power with the intake size slider. Generally this intake caps at 7k revs, but offers more noise and will induce higher maintenance costs.
  
• Performance High: The highest end intake that still has an air filter, designed to give peak power at roughly 8k to 10k revs while also having quite a large effect on intake resonances which can be moved around with intake size tuning.
  
• Race: Dispenses with the air intake entirely, and offers the most "peaky" engine performance best at and above 9k revs. Really only ever used on dedicated track cars for absolute maximum performance at the cost of tanking reliability (eating dirt isn't good for an engine) and being quite obscenely loud.

I won't cover all of the fuels here, as it's a relatively simple choice. Higher quality fuels have higher octane, and that means you can do more with the same amount of gas, without it exploding prematurely. Leaded fuels will be banned at various dates within the game, as lead in the air is bad apparently. It's important to also remember that fuel availability varies. If your engine can only run on Ultimate, you probably aren't going to be selling the car anywhere other then the most developed of countries.


How much fuel relative to air is in the fuel mixture. A 14:1 fuel mixture ratio is a 14 air to 1 fuel particle (or mole) ratio. Running the engine on less fuel, or "leaning out" the mix is usually good for economical cars but can induce knocking if the ratio is too lean. Running richer mixtures generally delivers more power at the cost of fuel efficiency. All fuel systems also have a maximum AFR spread that they can distribute fuel efficiently with with carbs being overall the worst at this and injected engines potentially having a high effective range.


With the addition of 4.2, ignition timing is now dynamically handled by the game. If you want peak high end power, you generally want to have this graph meet the dark green division at the top of your timing map. For more economical applications however, you'll usually want the timing to be pulled at high power, so that the engine can run at it's most efficient at low load without wasting timing/fuel. The timing map is adjusted with compression mainly, flow, and the timing map slider, which will effectively treat the engine as having better or worse fuel. Advancing the ignition timing will usually ruin your engine reliability while offering some better performance, and generally positively impact hydrocarbon emissions. Reducing the ignition timing will improve overall engine reliability, but make the engine perform worse, makes hydrocarbon emissions worse, but might help with NOx.

This is the peak RPM the engine is allowed to achieve, and is the redline for the speed governor of the engine. Higher RPM means that you can spool up the crank even faster, but at the cost of reduced reliability due to the stress it inevitably causes. As mentioned earlier in the guide, it's okay to not max out the RPM if the peak of the power curve is at a low RPM, as people will only use power they can drive with. The RPM limiter will also affect ultimate top speed the gearbox will allow for. A very high speed engine will have a minimum gearing top speed of roughly 200 km/h, while an extremely slow engine will have a top speed around 121 km/h maximum.

The last step of actually assembling the engine would be the exhaust system. The exhaust is responsible for getting the waste products of the fuel ignition out of the engine. It's also a large factor in reducing the noise actually generated by the engine with mufflers which reduce the sound of the exhaust pressure. Which type of header, or piece of exhaust that hooks up to the engine will also affect the overall performance of the engine, and how big of a pipe that comes after that can help run the engine a bit more efficiently due to harmoniously pulling out the exhaust.

• Compact Cast: This is a relatively lazy, but acceptable way to get exhaust out of the engine. It's literally just a single pipe with holes stuck into it, hooked up to the exhaust. It's almost always going to damage the efficiency of the engine, since the exhaust won't move smoothly at all but it's dirt cheap to slap on there. These are fairly common exhaust headers, and are required to use the first emissions compliance part, the exhaust reactor.
  
• Cast Low: Instead of a single pipe, the cast is done in a way that the exhaust bends outwards of the engine for each piston chamber, and this overall provides better exhaust performance since the gas doesn't have to make sudden turns. This particular variant is designed for improving low end torque. A large majority of more economy focused engines won't need more than this.
  
• Cast Mid: A cast header designed to get decent flow at the lower/mid range of the RPM range, decent for cheaper performance cars or otherwise engines where you'd want some more power since the cast low header tends to constrict higher end flow.
  
• Tubular Mid: A lightweight, and overall bulkier exhaust header made of steel or aluminum. This type of header is very smooth, and is often useful for high power engines. It takes some time to engineer versus a cast though. A good choice for performance cars or for reducing costs in a company familiar with tubular headers, as cast does not translate to tubular and vice versa.
  
• Long Tubular: For when regular tubes aren't enough. This contrary to it's size is actually slightly lighter than regular tubular headers. The extra length is used to further encourage exhaust gas to leave the engine. Quite high end for racing or sport configurations generally.
  
• Racing Tubular: For when you want your exhaust pipe to be a work of art. The racing tubular set is a very long and intricate series of pipes which are designed to scavenge every last particle of exhaust out of the engine, partially by making sure each pipe is the exact same length, regardless of bulk. This cannot be mass manufactured, needing to be hand built, and takes an extremely long time to engineer. The best possible race exhaust header. These will only exist on hand made, super high end cars, such as Hypercars.

V series and Boxer engines can have either a single exhaust pipe, or two exhaust pipes, one for each side of their bank. Generally a single exhaust is going to be cheaper than a twin exhaust, since you don't need to double produce the trailing components, such as the catalytic converter (usually the biggest cost, since cats need rare metals) and the mufflers. However, a dual exhaust is usually going to be much more efficient for scavenging exhaust, and getting more power out of the engine, with a few very specific exceptions. Most configurations have exhaust pulses which don't line up properly to run together to a single pipe harmoniously. A flatplane V8, and a V12 can usually run well with a single exhaust pipe. Other engines are generally best with a dual exhaust. Dual exhaust is also able to make the engine quieter, due to the fact that both exhaust pipes can be smaller, and still release exhaust efficiently.

In '99, there is an option to also add a feature called a bypass valve. Generally it's only used on supercars for once they go over a certain RPM. It bypasses the mufflers and acts as though they don't exist at the cost of however loud the engine would be without mufflers. This makes for a car which can have a quiet cruising drive, while still also having deafening exhaust noise for racing giving the car a bonus for a quiet engine when measured for comfort, and a loud engine bonus for racing.

Generally, you want the exhaust pipe to be able to either just barely be large enough for the throughput, or actually choke down in it a little bit. An exhaust which is too open will overall actually cost power. An exhaust which is too tight will strangle the engine, and cause a variety of issues, including knock in some cases if clamped down too tight. Choking down on the exhaust "just right" however can lead to a higher power and torque peak.

See the Emissions section.

Mufflers are used to reduce the audible noise an engine makes, and there are three variants (assuming we ignore "none" as a variant). It's important to mention that the second muffler in the series is the muffler which will provide the most effective sound dampening. A straight through trailing a reverse flow for example won't be as quiet as if the order was reversed.

• Baffled: The basic muffler from the beginning of the game. It basically forces the exhaust through a series of nets to quiet down the exhaust. It's light, cheap and offers a good middle ground between flow reduction and sound dampening.
  
• Reverse Flow: A reverse flow muffler does what it says on the label, it reverses the flow of the exhaust back and forth through the muffler to reduce noise. It does it's job very well, but is the most expensive muffler, and it does cut into exhaust flow quite a bit.
  
• Straight Through: A straight pipe with holes cut into it, with some space inside for the gas to expand to the outer area of the muffler. It's not very quiet, but it doesn't restrict airflow much, and it will dampen the sound of the engine a bit.

Kilrob, one of the devs did a fantastic YouTube video on the topic some time ago, so i'll link the video here.

Warning: It starts with math.

The bane of many campaigns in automation and the real world automotive industry. Emissions are what ultimately will kill your power (and eventually efficiency) values. I'll try to give you some guidelines of how to deal with each flavor of bad emissions here but it's also pretty important to remember that everyone's tune for their engine will be different and you may work yourself into a corner with some of these fixes.

Also generally known as unburnt/wasted fuel will become more pronounced with richer fuel mixtures and are especially prevalent when using a carb due to the relatively inefficient mixing process.

A flamable and toxic gas made as a byproduct of engine combustion, typically more seen as a byproduct of burning fuel in general but can be converted into the safer carbon dioxide using after compression items.

Also known as NOx, is mainly the type of gas that causes yellow smog and is an acid. This will usually make itself known when you use a lean fuel burn and higher compression.

Early on in the game Fruinia will institute the first set of emissions standards which will focus on CO and Hydrocarbons. You can usually meet these standards early on by reducing compression of the engine as well as running the engine leaner. Then NOx becomes a factor in 1972 and pulling fuel out of the mix becomes less viable. However there are several ways to approach fixing emissions depending on how you wish to tune.

There are four types of exhaust regulation in Automation (EGR is factored into cam more or less with quality).
Exhaust Reactors are a very pricy, unreliable, and still pretty bad option for dealing with emissions, but it generally will kill hydrocarbon and CO emissions due to the way it functions. It needs to be installed very close to the exhaust header input itself so it can only be used on compact cast headers. This can also be used in conjunction with leaded fuel. This first option is available in '65.
Catalytic Converters are marginally less expensive and restrictive, but can't be used with leaded fuels, the two way first becoming available in '72. It will function much like a reactor except it can be used with any header at the cost of efficiency as you use increasingly longer headers. The three way is the main method you will be using post '78 by default as it will scrub the exhaust of HC, CO and NOx combined. Catalytic converters do their job best at just above stochiometric ratio for the fuel which you can directly adjust where in the fuel map those values are with the fuel map and emissions optimization buttons. Later in the 90s, the Pre-Cat will become an option which serves to reduce undesirable exhaust gasses before it reaches the catalytic converter. Generally pre-cats should be used on larger, older engine trims, but can help with newer sportier engines if you are having trouble getting emissions down. Pre-cats can be used on any exhaust header up to tubular mid, at which point it is no longer possible to use on anything longer.

Higher emissions optimization might not always be better for emissions! As the fuel mix is forced higher up in the fuel map, you may experience a case where emissions optimization actually causes you to go over your hydrocarbon or monoxide budget.

• Carburetors suck for dealing with emissions in general. You will have a much easier time dealing with emissions switching to injection.
  
• It is technically possible to pass WES 11 using carbeurators, but typically the engine would be running in the category 1 WLTP cycle, and the car as a result will likely be highly undesirable with no actual power.
  
• More carbs will make hydrocarbon emission worse while improving CO emissions generally.
  
• More complex valvetrains can allow you to skirt emissions due to their cleaner flow of air leading to less undesirable burns.
  
• Cam profile matters a lot for hydrocarbon emissions. Overlap/blowthrough straight up adds fuel to the exhaust! Less cam, less fuel, less emissions.
  
• Compression is also huge for NOx emissions as well as the fuel mixture. A very strong compression engine with a lean fuel mix won't pass anything after 1972. Lower compression and richer fuel mixture fixes NOx. Ideal fuel mix to avoid NOx is 14.6:1.
  
• Fuel Ignition margin can help you tune for specific emissions with reduced timing helping with NOx and advanced timing helping with HC.
  
• Early game you'll probably fight emissions by running lean, late game you'll tend to run rich while using electronic injection.
  
• Power output matters. The game uses the WLTP emissions system, which means cars are tested based on their power to weight ratio. Sometimes having a weaker engine can get you passing while sometimes more power will too. All depends on the tune.
  
• Choking the engine will usually help with emissions in general. Less overall airflow means less fuel injected.
  
• More compact exhaust header styles improve overall emissions due to a shorter path taken to the catalytic converter, in turn improving efficiency as the cat works better with hotter gasses.

Engine design warnings are relatively easy to fix, fortunately. This section here will cover the warnings you're likely going to run into. Keep in mind, you aren't actually required to fix all of these issues if you don't want to. If the engine fails as a result of the issue though (red warning), you won't be able to use the engine in that configuration.

• Engine Doesn't Fit:
  This means that the engine is simply too large physically to fit into the engine bay of the car in the orientation desired. You can try placing the engine in a different location/direction, or you can reduce the bore, which will bring physical size down. Some engines simply won't fit in certain cars/configurations no matter what you do. This is NOT the same as a full engine bay.
  
• Engine Bay Quite/Very Full:
  This warning will show when the Fill Factor of the engine starts to reach 80% of the engine bay available space, and swap over to the very full warning once you hit +100% engine bay fill, though the engineering time cost starts at 40%. Automation just shows the engine itself in the engine bay, but your engineers will still have to figure out how to squeeze in the other necessary pieces like coolant tanks and batteries, a full bay makes this very difficult. Going over 200% means that the engineers will have to engineer the entire mount section around the engine, and that can get painfully expensive on anything that's not a Hypercar. One of the most obvious, and easy fixes is to reduce the bore of the engine. Other fixes can include using a tighter valvetrain, a non performance or race intake and a smaller exhaust header. A cast log for example takes up almost no space compared to a tubular exhaust header. Turbochargers also take up quite a bit of space as well, since they need to be placed a bit away from the engine, and have their own sizing dimensions.
  
• Engine Lacks Clearance To The/Is Very Close To The X Side Bay Wall:
  This warning will show once you make the engine large enough to start to run against the outer edges of the engine bay walls. Depending on the engine arcitecture, and drive type this can happen on any side. The closer to 100% fill you get, the higher the engineering cost gets. Shrinking the bore is usually the only way to fix this, short of completely changing out the engine, or swapping the drive type as a whole to something that would use less space (such as front longitudinal RWD versus front longitudinal FWD).
  
• Engine Is Knocking/Failed Due to Knock:
  In this case, you are applying too much pressure to the fuel, or are not giving enough fuel relative to air for the fuel to not preignite with how you've set it up. Enriching the fuel mixture, making a more aggressive (high) cam profile, and reducing compression can fix this. Making the bore smaller may help as well, but costs displacement. Turbochargers don't operate well with high compression engines in most cases, and will usually cause significantly more knocking, since the pressure they generate is exacerbated by the piston compression as well. Lower boost or compression ratios will fix the issue in most cases if a turbo is used. Strangle can also be a cause. Generally if the intake is throttling power by 30% or more, it will increase octane emulating a lack of airflow and fuel into the pistons, and as a result the likelihood of knock. Same holds true for a too small exhaust pipe, or an exhaust header/manifold not able to keep up, as the hot exhaust will get stuck in the piston on the next ignition cycle since it can't flow out.
  
• X Experiences a High Torque Load/Fails Due to Torque:
  Torque is a factor of power the engine can output, but it's also a source of stress on the engine parts. Reducing power output, such as by running leaner fuel is one option to fix this. Running a lower cam profile is another option in some cases, but could actually make the issue worse. Opening the exhaust may help a bit, since a more open exhaust generally trades torque for power. Using higher quality parts, via slider, or swapping to forged/billet/heavy duty materials can help as well.
  
• X Experiences a High RPM Strain/Fails Due to RPM:
  RPM will affect parts similarly to torque. Higher quality parts are more resistant to RPM strains. Running the engine at a lower RPM peak is another obvious solution. Shortening the stroke will create components which don't have to travel as far as quickly, and significantly reduces stress due to high RPM.
  
• Engine Experiences Valve Float:
  Increase the cam profile, use a different valve train, or reduce engine RPM. Valvetrains with more valves are more resistant to valve float. Reducing the size of the bore can help too, since the valves will be lighter and work with the springs better.
  
• Engine is Underpowered/Very Underpowered for the Car's Weight:
  Simply make the car output more power. You could also lighten the car itself, but this is more difficult to do normally. Generally, a yellow warning here can be ignored for extreme budget cars with early I3/4 engines, however a red warning is basically undrivable. Ideally, you want to avoid this warning if you can though. A yellow warning will show up if the car has less than a .025 power to weight ratio, and red warnings will show if the car has a .01 power to weight ratio.
  
• Engine Is Too Unbalanced And Cannot Run:
  Inline 3 and 4 engines (as well as flatplane V8s and V6s in both configurations) have a maximum size they'll reach before the smoothness starts to drop too much. If the engine has 25 or less smoothness, then the internals will lose ability to handle stress due to the sheer imbalance of the engine while it runs. If the engine has 0 smoothness, then the engine will be incapable of running, at all, even if the components can normally still take stress. As bottom end tech becomes better, this goes away over time as standards improve and engines naturally become smoother.

Everything in Automation has stats, and usually an associated chart to go with it. You obviously want to aim for the highest stats possible, every time, right? Nope! Price in particular is a dealbreaker if it's over what your target can afford. High stats usually mean high prices, amongst other things.

Each demographic (and each country's population separately) cares for specific stats, more than others. A person buying a City car, to get them to work and back home, and maybe to the store, probably won't care too much about the top speed of the car for example. While on the other hand, a Muscle car driver very much cares about that speed, and how quickly they can get there. The person buying the car for Offroading probably won't care about either, and is more concerned whether or not their car will get stuck in the mud.

The key stats in this list are usually the core of what determines what market the car is intended to be sold to. These stats are an aggregation of all of the stats which are associated with the field, with a multiplier adjusted up, or down based on how well the car does, or doesn't meet the required features to get a good score here.

• Drivability: Is a rough estimate on how easy the car is to drive for the average individual under reasonable conditions for everyday life.
  
• Sportiness: Is a rough estimate of how well the car performs when pushed to it's limits, how well the car facilitates getting to that point, as well as how well the car "feels" to the driver while under race conditions.
  
• Prestiege: Is an estimate of how "fancy" the car is. Bigger cars, bigger, more complex engines and more exotic/expensive materials and interiors are a major player here.
  
• Comfort: Is the driver sitting on a brick, or a hand crafted seat designed for the lowest possible discomfort? This is a measure of how comfortable the car is to drive for long periods of time.
  
• Safety: Most people don't want to die if the car stops as a result of something that isn't the brakes. Safe cars are almost universally better than unsafe cars. In many cases, cars will be banned from sale and road use if too unsafe.

• Practicality: How easy is it to get in/out of the car? How easy is it to put stuff into it, or take stuff out of it. This is particularly important for quite a few demographics.
  
• Footprint: How big is the car? Can two of them fit in a lane? The footprint of a car matters widely for different demographics.
  
• Utility: How much stuff can you load the car down with? Does the car function well when fully loaded down, or do the brakes melt immediately when you try to stop the car?
  
• Offroad: Can the car be taken off roads, or is it purely a track car which explodes when even thinking about dirt/rocks?
  
• Fuel Economy: How far can you go from Point A to Point B with X amount of gas? This is extremely important for budget focused buyers.
  
• Reliability: Essential to most lower range markets but valued by every market to a degree. A car that blows up after 40k (insert your choice of unit here) is not going to be highly valued.

Different demographics will have different desires for a variety of other statistics, such as engine size, and quite a few other factors. These will be covered later after we cover design of the car itself.

Designing the car itself is a little bit complicated the first time you've done so. Both in terms of visuals (I don't cover this, as i'm bad at it), and in terms of how you actually want the car to perform.

The very first step was selecting which type of chassis and suspension the car was using, and then you have your now (hopefully) completed engine. The last, and most important part is putting all of those features together into a trim. The trim is where everything you've done so far finally comes together.

The trim determines what type of body the car has, and what the consumer interacts with almost entirely. I'm going to try and show as many trims as possible, and explain the markets that tend to buy them.


Your typical four door car with some trunk space in the rear (or front if the engine is in the back). Most demographics don't care either way about this car. For the demographics looking for Coupe like cars, they will be slightly unhappy with the Sedan, but they will settle for one in most cases. Generally, the only market that really cares to have this type of body are the premium markets in general, and the commuter market. As of 4.0 this encompasses more of the more "generic" car bodies which aren't explicitly intended to be "sporty" even with fewer doors.


Similar to a sedan, but instead of four doors, the Coupe only has two. Some models still have room for rear seating, and some don't. This type of car is sought after by quite a few markets, especially sport oriented audiences, since they tend to have less drag, and overall have a smaller space, which appeals to sport buyers. As of 4.0 coupes are mostly restricted to purpose built, "sporty" bodies.


The hatchback is similar in many ways to a Sedan and Coupe, in that they often share the same form factor, but generally tend to lean more compact. They can have 3 or 5 doors. The odd numbering on doors meaning that the back can open on the car, hence the term Hatchback. This is generally sought after by city car buyers, since it's easier to load and unload cargo into the back for shorter trips.


The wagon is essentially an elongated sedan crossed with a hatchback. Due to their added space in the rear, they tend to appeal more to family oriented buyers, especially the family utility market.


Convertibles are usually Coupe model cars, with the option to collapse the roof back into the car. They are only sought after by people looking specifically for a convertible. They do tend to bring in more money though, since they are all about prestiege. A soft top convertible isn't as good as a hard top however, and will incur a small penalty there. One quirk of ladder frame is that you don't need to pay extra weight to reinforce the chassis on a Convertible. On any other chassis however, extra weight will go into reinforcing the frame.


Or, Sport Utility Vehicle. Sought after by the utility sport market, obviously. These are fully enclosed, and often large, boxy cars with very minimal overhang which are intended for offroading, hauling, and even towing.


Sought after by the Pickup markets for their ability to pick up and haul a massive amount of stuff, as well as tow a few things here and there with an open bed. They don't need to be taken offroad, but it's often better if they are able to do so.


Basically a big box with an engine on the front. Their entire focus is on cargo area of the car. The van offers the best possible cargo space of all trims. This is sought after by delivery companies, but often not much else.


Basically a van converted into a large taxi. Sometimes referred to as minivans or a MPV (Multi-Purpose Vehicle). People movers use their large area to squeeze as many people into the car as possible. This is the car trim of choice for the MPV market, does well for a Passenger Fleet car, and it also may carry over into the family car market if setup correctly.

This section was originally part of the Drivetrain section, but drivetrain itself got split out in the game in Al Rima.

The gearbox is where the torque your engine makes comes into play, as the gearbox uses that torque to apply the power the engine provides, as you likely saw in the video above on torque versus power. It does so by multiplying (usually at low speeds) or dividing (at high speeds) the torque the engine outputs using gears which have different ratios of teeth. This helps to regulate the speed of the crank in the engine itself, while also regulating the car's speed, and allowing for much greater freedom in how fast a car can go.

• Manual: A manual gearbox is the classic "stick" gearbox, where the driver has to manually select which gear the car is driving in. This is (arguably) the best sporty gearbox, and it doesn't have any parasitic drag to be noted. A manual will probably be used throughout the entire game for your sportier trims. Manuals are usually the cheapest and most reliable option.
  
• Automatic: As would be expected, an automatic gearbox does the work of shifting for the driver. This variant does so via mechanical computer and hydraulics. It makes the car overall more drivable for the average user, but has a fairly significant parasitic loss on the power of the engine due to the way it works, and it as a result is notably inefficient with the fuel. Solid choice in the early game once unlocked for more premium cars or into the 70s and 80s for more normal consumer cars.
  
• Advanced Automatic: Similar to a regular automatic, but computer assisted. This helps reduce overall losses caused by the basic automatic transmission, and can be switched into different modes, making the transmission viable for some sports cars, though a manual would still be superior for sportiness specifically. A good choice all around once unlocked generally.
  
• Auto-Manual: A computer operated manual transmission which is operated via buttons. This allows the driver to select the gear in a sequential order, and the computer handles the clutch and gear swapping for the driver. This can optionally also be used as an automatic making it a good all-round transmission choice which isn't much more expensive than a manual.
  
• Sequential: A much rougher and responsive lever based variant of the auto-manual designed to be lightweight and extremely responsive above all else using a helical gearbox. Includes a manual clutch. Really only intended to be used on track oriented cars, but can work in sportier models.
  
• Dual Clutch: Very similar to a sequential, but with two systems built in. One computer handles even gears, and the other odd. Functions mainly as an automatic, but allows the driver to override the computer, if so desired. Nearly instant gear swap due to having two computerized clutches. A very solid and usable choice for higher end cars in general, but probably shouldn't be used in cars where comfort is priority.
  
• Continuous: Also known as the CVT. Effectively removes the conventional gears of the car replacing them with a pulley on two rollers which allows for a theoretically infinite range of gears up to a point. Technically the best gearbox to use for pure acceleration and efficiency, but tend to be extremely unreliable. Very sensitive to torque, and disliked by sporty markets due to the lack of driver control and usually causes a consistent droning noise from the engine as it's designed to hold the engine at a single optimal speed if it can. Potentially extremely useful on lower market cars like city cars, or super high range markets like Luxury due to the smoothness of this system.

A gearbox can have anywhere from a lowly two gears, all the way up to nine in Automation. More gears overall provides for better acceleration versus fewer gears, as each gear has an optimal range for acceleration that the gear will provide for. More gears also gives the driver or car the ability to run the car at a lower RPM while still achieving the same speed, as a result saving on fuel. The only real issue with adding more gears is the expense that comes associated with it, the weight it costs, and the engineering time to make a more complex gearbox, as well as potential reduced torque tolerances.

The top speed section is for how long the gears should be driven in, which is influenced significantly by the final drive gear ratio (which is the last gear to turn before the drivetrain turns), which this slider affects. A longer gearing allows for higher top speed. While a shorter gearing tends to lead to higher overall acceleration, assuming the driver can keep up with the shifts required for optimal acceleration. Top speed can also be used to create what's known as an overdrive gear if it's set high enough, where the engine doesn't have enough power to push the car beyond the torque/power peak in the final gear. This lets the car keep it's peak speed, while driving the engine at a lower RPM, and as a result saving fuel.

Spacing is how far apart the gear ratios are from each other. Higher spacing generally means more application of power sooner in the initial gear and faster acceleration while shorter spacing means each gear applies it's power slightly longer at higher speed before needing to be switched to the next gear. Higher gear spacing, especially on cars with many gears is generally more comfortable for the driver to operate, but tends to make the gearbox heavier, and past a certain point induces unreliability. Tighter spacing lets the driver keep the engine at peak power for longer, which is beneficial for sportiness and results in a lighter gearbox.

Faster acceleration means faster 0-100 times, but it also means that the car may encounter loss of grip and tire spinning. Grip loss can be partially fixed with the differential. It's generally suggested to have one gear set to achieve 100 km/h for in game stats on the 0 to 100 times.

The speed limiter is used with electronically controlled fuel injection systems. Without setting a peak speed, the engine is not limited on how fast the car can go, and is instead limited on either the gearing, or the power of the engine itself. Adding a limited speed can be used to force the engine to cut fuel flow past the set speed, for fuel economy reasons, as well as tire cost limiting. Tire cost goes up if the car can go faster, and forcing a cap reduces required tire speed ratings.

The differential is what allows a car to turn without twisting the axle, since one wheel moves faster than the other in a turn.

• Open: The simplest as well as most common differential type. The open diff will apply the most power to the wheel which gives less resistance. This has the benefit of being rather cheap, but it will basically make the car useless on any road surface that's icy, or muddy. It's usually actively detrimental to getting a car unstuck, since the stuck driving axle will send (almost) all the power to the free spinning wheel.
  
• Manual Locker: Allows the driver to manually lock the axle together to ensure both connected wheels run at the same speed. This is generally unnecessary on most cars, and will be seen as simply an extra cost in some markets for a feature they don't use. It causes binding of the axle and diff in turns on pavement, which tends to destroy the diff. However, it's extremely useful for offroad driving cars, as locking the axles prevents a car from getting stuck in mud as firmly with the tires locked together. One tire should in theory be able to grip the surface, instead of just spinning the free wheel like an open diff does.
  
• Clutched LSD: The clutched LSD is available in the year 1957 is uses a series of clutches in between the tires to allow the wheels to spin at similar speeds when experiencing lack of grip, but also allows for some slip when the axle overpowers the force of the clutching action. Overall a very harsh LSD system, but is very useful for keeping grip and putting down power, as it's one of the highest power LSD system at the highest cost before electronic techs come along.
  
• Race Clutched LSD: Similar to the above, but much harsher locking action and much more expensive. Will provide the most traction of any diff type except for the Advanced Electric diff type that comes late game.
  
• Geared LSD: Available in '81. Unlike an open differential, this system tries to apply the most power to the wheel that gives the most resistance to turning. This in turn reduces grip loss across the board, and usually makes the car easier to drive hard. This is a somewhat complicated and expensive piece to put together. It's also not the most comfortable diff either, since the diff tends to be a bit more "forceful" during acceleration.
  
• Viscous LSD: Available in '85, this LSD uses a special type of Silicon that heats up and hardens if the wheels aren't spinning the same speed. That helps to partially lock the wheels together and improves grip. It's relatively cheap compared to a geared setup, but not as efficient. It is a decent choice to reduce traction losses on luxury cars however, since this diff generally wont be noticed unless it's activated via a spinning tire.
  
• Electric LSD: Electronically controlled LSD using hydraulics and electronic sensors to detect and reduce wheelspin and traction loss. Very expensive to produce and engineer, but does the job exceptionally well.

The wheels are what make the car move, and also what make the car stop. They're also notorious for mixing measurement systems because we've decided that it's okay to do that apparently. The wheels and the suspension are key in how your car performs in almost all respects. The engine applies power to the wheels, the wheels move the car.

There are only two types of tire construction. Cross Ply (sometimes also called Bias Ply), and Radial tires.
The major difference between the two is that cross ply tires typically have their layers applied at a 60 degree angle relative to the rim. This gives them stiff sidewalls, and and as a result they are more accepting of weight for their size. Unfortunately however, they are difficult to make wide as a result of the way the ply is applied. They tend to have a poor cornering grip for their width versus a radial of equal size, but generally have more straight line grip. Cross ply tires have an additional speed multiplier cost on high speed cars.
Radial tires on the other hand are produced by running one band of the material across the entire tread of the tire, and another layer across the rim. This makes a tire which is easier to make a bit wider, but overall has weaker sidewalls, and can't hold as much weight on them. The weakness of the sidewalls in Radial tires make them a poor choice for offroad cars until around the '70s when the issue with radial sidewalls are fixed. Radials will be pretty expensive at the time of their introduction, but over time, they will surpass cross ply in terms of price and performance, especially at the upper limit of what the cross ply construction method can offer. A wide as possible cross ply will usually end up quite a bit more expensive than the same size tire in a radial form.

• Chunky Offroad: Essentially snow/mud tires. They're usually a terrible choice on anything but specifically offroad cars. They also have the least grip of all the tires, making them overall bad at helping the car corner, or accelerate.
  
• All Terrain: Tires designed to be a middle ground between hard long life tires and chunky offroad tires. Still able to offer good on road performance while having a desirable tread pattern for gravel, mud and snow.
  
• Utility: A tire designed for maximum carrying capacity and longevity. Results in an uncomfortable ride, but lasts about as long as hard long life tires, and has substantially higher carry capacity.
  
• Hard Long Life: A hard rubber and construction and easy to produce tread make up this tire. It's cheap, and since the rubber is hard, it helps with fuel economy. It's also got a bit more of a weight capacity, since it's built a bit sturdier. It's not fantastic in terms of grip, but it works, and it can easily be driven.
  
• Medium Compound: Middle of the road tire compound. Not too hard, not too soft. Great for most models of car, especially comfort focused cars, such as premium models.
  
• Sports Compound: An even softer rubber makes up this tire type. It's a bit more difficult to drive with, but it has quite a bit more grip, and it noticeably improves cornering. Pretty much the only choice for sports/muscle cars. Unlocks in 1953.
  
• Semi Slicks: Basically race tires made legal for the road. Extremely soft, and rather expensive. This is the tire for when you absolutely need the highest grip and cornering possible, and don't care about the cost, nor economics. A good tire choice for high performance sports cars, or track cars. These tires are extremely niche however, and can be detrimental to quite a lot of more common man focused trims. Unlocks in 1997.

Sizing of the tires is a major factor in how the car will handle, and can vary from situation to situation depending on how the weight is distributed across the car.
The key to understanding how your car will perform with different tires is determined by the charts in the above image.

Depending on who you want to sell the car to, you'll want one of the two dots on the yellow line on the center graph there to be as close as possible to either the red, or blue line. Going below the blue line means that the car will understeer, or go wide in a turn. Keeping the drivability dot on the blue line implies that your car will be where most people would consider extremely drivable, but not very sporty. The red line is the target for the sportiness crowd, as they tend to like being able to drift a little bit. Going over the red line causes oversteer. Oversteer means that the back end swings wide, and the turn ends up going even tighter than intended, or even spinning out the car. If the chart shows the line actually going UP. Then you have what's known as terminal oversteer. That means that at that point, the car will become literally undrivable, as the car will spin out at higher speed with minimal input. The sweet zone for steering is right in between the two.

If your car is understeering, you likely need to widen the front tires or narrow the rear. If your car is oversteering (or doing so terminally), you need bigger rear tires or smaller front tires. It's a bit more complicated based on the individual car situation however. If you can match the wheel sizes though, you do tend to save quite a lot of money. You by no means are required to though.

Traction is heavily influenced by the tires, as well as the gearing for the car. When a car suffers from traction loss, it's because the engine is outputting more power than the tires can actually grab onto the road with. Smaller tires are more susceptible to lost grip, but they also generally accelerate the car faster for the same amount of applied power. Larger tires are less susceptible to losing grip, but as a result of their added size, accelerate slightly slower. You can see the tire effects of traction losses on the grip chart. In the case of the car shown there, there is ample grip for the front tires to handle the power the engine will put into them. If you see the acceleration line (shown in yellow) following the tire grip line, you're maxing out the grip the tire can provide, and encountering wheelspin and traction loss. All wheel drive cars are less susceptible to wheelspin and lost traction, and the chart gets more complicated for that specific case.

The rims determine what type of alloy the rims themselves are made of. Steel is the cheapest option. HD steel are more solid builds of rims making them less susceptible to damage if bumped or in offroad conditions. Alloy is lighter than steel but twice the price, and magnesium is lighter than both but very expensive with forged rims being lighter than magnesium but more resistant to offroad conditions. All of which reduce weight on the wheels allowing for faster acceleration, but usually cost a little bit of grip as a result. Alloys and mags don't like dirt however, and steel rims are best for offroad models. Carbon Fiber exists, but is extremely expensive for the weight saved and the prestiege gained.

The size of the rim relative to the whole tire is important as well, for the tire profile (the difference between the sidewall height relative to the width of the tread) and how much weight is applied as unsprung mass to the tires. Generally, a larger rim will provide more grip to the tires than a smaller rim, since each tire weighs a little more. Lower profile tires are generally sportier, and better at cornering, while high profile tires are more comfortable since the rubber can more effectively isolate the vibration of the road before it hits the suspension.

Tires have different costs associated with the car going faster, this is to reflect the effort which goes into making sure the tires don't literally come apart at the seams at high speed. Note, this table was made for a 2012 model car, year shifts the prices significantly in earlier years, to the point where a relatively "normal" Q class tire costs five times what's seen here. I'm missing a few tires at the very low end of speed as well but generally if the car is that slow, it's going to be undesirable past the 1950s.

Tire cost can become extremely inflated if the car can go over 300 km/h, as can be seen easily here, and as a result, unless you're selling a hypercar, this is one good reason to keep power under control, as well as sometimes shoot for lower grade tires than would be expected. (Y) class semi slicks for example are stupidly expensive compared to (Y) class sports compound tires. Both of them are almost triple the cost of a "standard" Y class tire.

Tires across the world have a universal system of measurement. The measurement works as follows, using this example.

225/70 R17 N113

225 is the entire width of the tread in millimeters.
70 is the aspect ratio of the tire, or what percent the sidewall height is relative to the width of the tire.
R is Radial, C is cross ply (which will be in place of the R).
17 is rim diameter in inches.
N is the speed rating, as shown above.
113 is the Load Index/Rating, which is measured per tire. Multiply the load index actual weight capacity of each tire by four to get the max load the tires can handle. I have provided most common load indexes here, but it is possible to make tires with less load index in automation, though they start to become a bit... memey below Index 70. Look it up if you want.

The brakes on the car are one of the critical components in the car. "If the brakes won't stop it, something will" is not a good motto for a car designer. Basically everyone wants to have good brakes on their car, regardless of the demographic, unless it's before 1960, and people don't really care. Another neat little detail about tires, and grip is that the brakes need to be able to use the tires to actually stop the car. Making very grippy tires for example, and putting bad brakes onto them is usually not going to go over well with the consumer, since the brakes won't completely lock/stop the tire. Tiny tires will give bad braking distance compared to larger, and wider tires in general. Ideally, unless you're building a utility vehicle, you want just enough brake force to lock the wheels. That means matching the force to the grip the tire can provide if possible, without going too far over, especially before ABS is invented. Utility vehicles need brakes which DO go over the normal locking threshold, since they weigh down the vehicle more, giving the tires more grip, and more mass that needs to be slowed down. After ABS is available, there usually isn't a significant penalty for exceeding brake force relative to tire grip, unless the brakes massively overpower the tires.

• Drum (Single Shoe): The drum brake is the first, and only brake available at the beginning of the game. It operates by having a "shoe" inside of a sealed drum. When the brake pedal is pushed the shoe starts pressing against the inner edge of the drum which spins with the wheel, slowing the car down. They are usually woefully inadequate at the job, but they are cheap. Single shoe drums rarely work well with front engine vehicles, but mid/rear engine vehicles can sometimes scrape by with single shoes due to lack of mass, and therefore grip up front.
  
• Drum (Two Shoe): Same as the above, but with another shoe on the other side of the drum. These are acceptable brakes for a front engine car, and might actually be preferable on certain types of cars, like offroad vehicles due to the fact that they are sealed. The two shoe drum can only be used on the front however as the rear axle assumes to have a hand/parking brake that takes place of the second shoe.
  
• Solid Disk: The solid disk is what it says on the tin. It's got a solid disk of metal that spins with the wheel, with a brake piston (or six) holding the brake pad. Once the brake pedal is pressed, the pistons squeeze down on the brake pad causing friction slowing the car to a stop. The solid disk is generally slightly better than a drum of equal size with a single piston, and has much more surface area to dissipate heat over. This makes them very appealing to use as soon as they are available. Extra pistons allow for smoother, and more comfortable brake application, as well as stronger brake force.
  
• Vented Disk: Similar to a solid disk brake, but with vents inside the brake to allow for additional airflow to cool the brake, and as a result the brake pad, in turn helping to reduce brake fade. Vented disks are extremely useful for front engined cars, especially utility models. Most cars will experience more fade on the front brakes than the rear, which is where front vented brakes come in handy, as weight shifts forwards during braking.
  
• Carbon Ceramic: A stupidly expensive brake type which basically never has issue with brake fade unless the rotor is comically tiny. These are usually reserved for super premium sports cars, supercars and hypercars. Using this brake rotor will induce a limited production tag on the car.

With brakes, bigger is better. The limit for how large of a brake you can put onto the tire is determined by how large the rim is. Bigger brakes offer more force due to leverage, and are resistant to fading (overheating and becoming less effective) as there is greater surface area to soak/dissipate heat. More brake means more brake pad however, which can get quite expensive very quickly.

Pad type is what type of material the actual brake pad should be made of. Lower brake pad type leads to a more comfortable brake pad, since the material may be made of a softer material such as rubber, or something similar. Higher numbered pads on the other hand are usually harder and more expensive brake materials or ceramics, including even steel on steel brake pads at the high end. They are incredibly uncomfortable, but highly resistant to fade.

Aero is relevant for most cars. Drag and lift (or downforce) for example affect how well the car will perform at increasing speeds. Various undertrays are available as options to help reduce the drag and lift on the car (sometimes undertrays can make the car lift more, depending on trim). Late game there's even an option for a downforce undertray which instead of causing lift, pulls the car down.

Lift can be good or bad. Lift means that there's less weight being applied to the tires, which usually means less grip, and a more dangerous high speed steering profile. On the other hand, lift reduces weight going towards the ground, and might help with acceleration and economy a bit.

Downforce is the opposite of lift, and is provided with wings and lips as fixtures, or undertray options. Downforce gives the tires more grip enabling them better steering at high speed, at the cost of said speed since the engine has to push more effective weight forwards.

Additionally, there are active technologies, such as an active wing, and cooling flaps, which do a variety of things.

An Active Wing tells the game to treat the rear most wing as an active wing. What that does is instead of the wing being a static simple wing, it adds hydraulics to the wing which allows it to shift position as the car increases or decreases speed. This allows for higher downforce, while also reducing drag at the cost of weight, complexity and monetary cost of the hydraulics. This is generally only used on Super/Hypercars and occasional sports or track cars.

Lastly there's cooling airflow. Cooling down the engine keeps it cool, and running reliably. Not cooling down the engine as much reduces drag, and may actually help with fuel economy, at the cost of potentially damaging the engine.

Cooling Flaps are somewhat pricey, but they allow for the engine to have a higher cooling capacity while also bringing down the effective drag that would normally be caused by having larger/more air inlets. This is usually done with electric actuators controlled by internal thermostats which open or close the vents as required to keep the engine running at the optimal temperature. This can be relatively expensive depending on the model of car and the target market, with a normal cost of $200 in materials alone. Cooling flaps are usually only worth adding onto Utility vehicles, and occasionally eco focused cars in countries where reliability particularly matters, allowing for high airflow when needed and low drag/high fuel efficiency when not. They can also be added to sports cars for maximum drag reduction, though this generally offers next to no benefit if airflow is designed to be below recommended (below 50, or 100% required flow) levels.

Brake airflow is a slider determining how much work goes into ensuring air can pass over the brakes and pads, which will in turn enable the brakes to cool off quicker with more exposure to moving air. This has some impact on the aerodynamics of the car, and will usually slightly reduce top speed, and make fuel economy marginally worse, but it is a viable option on cars where large brake rotors simply won't cut it. It is an additional cost of up to at most 6 months of engineering time, but can be well worth the investment, especially on sporty, or utility oriented cars.

The interior of the car is rather easy to figure out. Better interiors are more expensive, and more comfortable. End of story, right? Kind of.

The interior that you choose will have a variety of things that they do. Bench seats, while often necessary for family demograhics are rather uncomfortable. Putting more seats into the car will often be uncomfortable as well, since more seating means less space for actual people. It's going to matter significantly which car you are going to be doing the seating for. A sports coupe with only one row of seats has no business having a three person bench seat in the front. A commercial van on the other hand might need that third seat however for practicality. Additionally, you can add optional rear seating into most cars which have more than a single seat row. They aren't the same quality of seat as a full additional seat, however, most optional seating is just that, optional. That means that the seats can generally be folded down, or are designed in a way in that they CAN accept a person or reasonably accommodate cargo. Optional seats can allow a car to fit into multiple markets, and is a viable option on quite a few car types, such as Family Utility, or GT cars.

Each tier of interior quality (not the slider) is going to be more expensive, and heavier than the last except for sport, which is special in that it weighs in between a premium and standard interior. Higher quality interiors also have a benefit in that they offer better sound insulation against the engine, except for sport, which is specifically designed not to insulate against the engine. Luxury/Hand Made for example can almost completely negate the sound of many engines. Remember though that the interior quality tiers get more expensive as seats are added to the car. A twin seat hand made interior is going to be pricey, but usually not at pricey as a 9 seat people mover with a Luxury interior.

The type of entertainment matters as well. Newer entertainment costs the same as the previous tier in terms of mass and engineering time (assuming we ignore familiarity), but not cost. In some cases though, you'll have the choice between one type of basic or standard item. Usually people will want to buy the new format over the previous one, unless they're budget strapped, or the format is so new that putting them into a car is prohibitively expensive, such as the introduction year of a new format. Entertainment methods which are near to be phasing out, such as CD player only radios in the mid/late 2000's will be almost free to install since the format is more common. It won't be as good as an equal tier system of the next format, but the prince difference will usually be substantial.

Safety is extremely similar to the interiors. Better safety standards are (almost) always preferred, but safety can get weighty and expensive. Basic safety is the bare minimum, and might work for cash strapped budget buyers, or for people who just don't want the added cost/weight, such as track car buyers outside of Hetvesia. The issue with basic safety is keeping the car street legal, since it cuts out a lot of tech to barely scrape by. Standard safety is the standard, and should be normal for most trims. Almost every car you produce should have at least standard safety measures. Advanced safety is cutting edge safety, like a collapsing steering wheel column in the '50s. Advanced safety packages are expensive and heavy. However the investment is usually worth the cost, particularly in markets where safety is a huge concern, such as the Family market globally. Safety is the only factor in a car which increases the weight of the car through use of the quality slider, which is notable.

Power steering is almost required on some models of cars, especially once they start hitting over a ton. No matter what, power steering is going to be harmful to sportiness of a car, but improve drivability, though electric variable steering near the beginning of the '00s comes close to being as good as a car without power steering. Power steering, depending on the type used will generally remove the ability for the driver to feel the road when compared to a manual steering wheel. Power steering on the other hand significantly reduces the physical effort that goes into actually steering the car, and is almost always required on a steel panel, front engine car.
Rack and Pinion steering is usually more responsive to drive than a Recirculating Ball steering rack, but has a much harder time steering heavier cars, as the rack is as a more direct drive system compared to a ball rack. This applies to their hydraulic variants too. Variable steering racks wether electronic or hydraulic typically alter their steering assist based on the speed of the car which generally makes them much easier to drive, but induces some unreliability.

Drivers aids in most cases require an ECU, which means they can't use a carbeurated engine.

ABS doesn't need an ECU, and it helps to compensate for going a bit overzealous with the brake/pad type, since they prevent the brakes from completely locking up the wheels (which happens when the brake force exceeds the grip the wheel provides) and helps prevents uncontrolled stopping skids, and helps with braking distances during "panic stops".

Traction Control and Electronic Stability Control serve two similar purposes of trying to keep the wheels from spinning. They are a rather significant investment to engineer, but nearly every demographic appreciates it, unless they can't afford it, and they largely improve the car overall. Traction control is focused on wheelspin, and actually doesn't do much if the car doesn't produce enough power to spin the tires. ESC is traction control, combined with other equipment and tech to help the driver control the car in the event of a skid. That as a result directly adds to the drivability stat for steering the car.

Launch Control with ESC throttles the drivers input to the engine, restricting the engine RPM until "launch" is achieved, almost eliminating wheelspin in the process. Most demographics don't need launch control, since most drivers don't floor the gas at a standing stop. For demographics which do do that however, like Muscle, Sport, and Track especially, it's usually a rather large boost for desirability.

The suspension isolates the bumping of the wheels from the rest of the car. How the suspension is tuned also has a major impact on how comfortable, and how sporty the car can be. All suspensions have some form of spring, and damper. The spring keeps the car from hitting the ground, and the damper makes the spring not repeatedly bounce the car after leveling onto straight terrain. Sway bars are also covered here, and they keep the body of the car on the ground by holding together both sides of the car, reducing roll relative to the axle they're attached to, and the likelihood of a flip under normal conditions. On some cars, a sway bar is optional, but usually not.

• Standard: A standard suspension spring is usually a simple, single width coil that compresses when the car goes over a dip in the road. They are the most basic of springs, and as a result are dirt cheap to use.
  
• Progressive: Similar to standard springs, but made thinner or longer where applicable, and might be made of different materials at different points. These springs make for a more comfortable drive, at the cost of a bit higher manufacturing cost. These springs also have multiple spring stiffness values, and can carry double the mass of a standard spring.
  
• Hydropneumatic: Or, hydraulic suspension. This is an extremely prestigious suspension type, and very comfortable. However, it can suffer from major reliability issues, on top of cost. This pressurized system does allow for the most possible mass to be loaded however.
  
• Air: Instead of springs, the suspension in these types of "springs" push against compressed air. This makes for an overall good all round suspension compared to a metal spring at the cost of some reliability and engineering time.
  
• Active Sport/Comfort: Computer assisted suspensions intended to have multiple modes of use. Very comfortable or sporty depending on the type selected, but stupidly expensive. This system can typically carry an amount of cargo in between a progressive and air spring system.

• Twin Tube: The basic hydraulic damper. One tube presses against another filled with hydraulic fluid. It's not great, but it's reliable and cheap.
  
• Gas Mono-Tube: Generally better than a Twin Tube in all ways but cost. This suspension has a rod pressing against a tube of compressed gas.
  
• Adaptive: A complicated type of damper filled with a magnetic fluid which can be tuned for different work conditions. This is a superior damper compared to the other tube designs, but it's less reliable.
  
• Semi Active: Another superior damper, which tries as much as possible to cancel out the spring forces, typically using a computer to change damper characteristics.

• Passive: A simple metal tube keeps the body from tilting too far. Simple, cheap, and it works.
  
• Semi Active: Similar to a passive sway bar, but split in half, and attached to a hydraulic or electric arm. This arm acts to keep the car stable, and is overall better than a passive setup, if a bit costly.
  
• Offroad: A specific type of sway bar similar to a Semi Active sway bar, but with a driver operated toggle to disconnect the bar. This allows the axle to move free of the body of the car.
  
• Active: A fully active sway bar which works to ensure the maximum possible ride smoothness. It's expensive, and prestigious.

Lastly there is the suspension setup.

Camber of the tire refers to how much of an angle off 90 degrees the tires sit on the ground. A higher negative camber points the top of the tire inwards, and the base of the tire outwards. What this does is give the tire extra grip by using more of the tire on the ground. Camber is a good way to fine tune steering profile, though this does come with higher servicing cost since more of the tire is likely to be worn down.

Second is toe which points the tires inwards or outwards in order to change the handling characteristics of the car. Positive toe is toe in, and generally causes the car to trend towards understeer, while negative toe is toe out, which tends to induce some oversteer. Toe is very useful to play with in rear and mid engine cars, but tends to induce wear on the tires with costs passed down to the customer.

Third is the spring stiffness. A harder spring stiffness will increase the frequency of bouncing of the springs, so a harder spring generally will bounce more when going over a bump when used with the same dampers as a soft spring. Harder springs are uncomfortable since there's little "flex" for the driver and passengers, as they might end up absorbing most of the force instead. Hard springs make high speed driving more predictable. Soft springs are generally more comfortable, but can cause roll, and bottoming out issues. Stiffer springs can also carry a higher load capacity, provided the tires can handle it. Making springs stiffer generally cause the end with the stiffness to lose grip in the tires. Making the springs softer does vice versa since the tires can move a bit more freely compared to the body.

Fourth is the damper hardness. A hard damper will pretty much immediately smooth out the car after going over a bump. This is generally uncomfortable for the driver and passengers though. A soft damper will allow for more "bounce" in the springs, and is generally more comfortable. A good middle zone in damper hardness is good for making a drivable car though.

Fifth item is the sway bar stiffness. A stiffer sway bar keeps the car from rolling as hard in a turn. As a result of how they work, they also slightly influence grip of the tires, since the weight is applied to the axle of the tires themselves. It is possible to have 0 sway bar cars, but they generally need to ride very low to not have issue. Offroad driving cars are best with the minimum amount of swaybars possible.

Final item in suspension setup is determining how high the car should ride, or it's default ride height. Lower cars inherently roll less, and generally have to deal with less drag. Higher cars roll more, but can haul more, and give the driver a better field of view. Cars in the middle range tend to be more practical to get stuff in and out of. Each buyer wants a different ride height for their intended purposes.

Trims are vastly more complex than the engines themselves, since there are so many factors that play into them. Quite a lot of the issues you'll run into can actually be ignored if you've already tried fixing them to the best of what's available at the time, or outright should be ignored based on the target market. Bad brakes are an obvious example in 1946, since you're stuck with single shoe drums.

Drivetrain Related Issues

• Short Gearing Reduces/Significantly Reduces Car's Top Speed:
  This implies the obvious, in that the gear ratio of final drive is too short to use what power the engine provides, leading to an artificial cap caused by the gearing.
  
• A Lot Of/Excessive Overdrive Due To Long Gearing:
  Longer gearing can be used to make a fuel efficient overdrive gear. It will slow down the car overall, since the gears are longer and driven in for longer. This can be ignored in blue (a lot of) note status, but yellow (excessive) note overdrive just harms performance with little to no gain.

Wheel Related Issues

• X Tire Is Too Narrow For The Load It Carries:
  This implies that the tire is too small in terms of width to carry it's load. This will incur a minor drivability hit, usually. It will also reduce the load of what the car can carry. Narrow tires on a Van for example will give it good fuel efficiency, but hurt the cargo capacity, which will ultimately hurt your score.
  
• X Tire Is Too Wide For The Load It Carries:
  The tire might be a bit excessive for what it's carrying. As far as I know, there's no penalty for this, except probably requiring bigger brakes down the line.
  
• X Tire Profile Is High:
  A high tire profile means that the sidewalls are actually taller than the tire is wide. This makes for a fairly awkward to drive tire, and one which harms steering ability. Do not worry about this for pre-70s cross ply tires.
  
• X Tire Profile Is Low:
  A low tire profile means that the sidewalls are 40% or less tall than the width of the tire. This makes a tire that feels like you're driving on the rim.
  
• Car Tends Towards Understeer:
  The car doesn't turn as tight as it should. Making the front tires wider can fix this, as well as increasing the width of both. Reducing the rear size has less effect, but can help.
  
• Car Tends Towards Oversteer:
  Car turns tighter than it should. Making the front tires smaller can fix this, and reducing both as well will make the car oversteer less.

Brake Related Issues

• X Brake Force Is Low Compared To Grip:
  This implies that the brake is insufficient to actually lock, or almost lock the wheels on the axle they apply to. Can be fixed in a variety of ways, from brake pad improvement, to different brakes, to larger brakes.
  
• X Brake Force Is High Compared To Grip:
  This means that the brakes lock up the tire too easily, and makes the car overall harder to drive. Lower pad types, and smaller brakes can help here. This can be ignored for the back end of most utility cars, since they need a "grip reserve" to stop with full cargo load.
  
• Brakes Show Slight/Suffer From/Have Severe Brake Fade:
  This means that the brake starts to overheat, and lose braking force as a result of use. This generally only will show up when fade goes over 1%. Making larger brakes, with higher pad type is mostly the only way to resolve this, especially focused on the front, since weight shifts forward while braking.

Aero Issues

• Downforce Causes The Car To Bottom Out:
  Wings if set too powerful for downforce application will actually cause the suspension to completely collapse at high speed, completely bottoming out the car. Bringing the wing angle value down, or raising the car helps to eliminate this.

Drivers Aid Issues

• Weight And Lack Of Power Steering:
  Depending on the weight distribution of the car, and total mass, a car may require power steering to be drivable. Adding power steering, or lightening the front of the car resolves this.

Suspension Issues

• Car Is Bottoming Out:
  The body of the car hits the ground after a small bump in the road. Use stiffer springs, or raise the body of the car.
  
• X Dampers Are Hard:
  If you're making a sports car, you can usually ignore this. If not, a hard damper is uncomfortable.
  
• X Dampers Are Soft:
  Generally a soft damper warning shouldn't be ignored except on premium, and luxury cars.
  
• X Ride Frequency Is High:
  This generally won't happen unless you completely harden the springs. A high ride frequency is good for sportiness, but bad for everything else. You can ignore this on the rear springs of utility trucks and vans however, since the extra spring hardness is used to carry cargo.
  
• X Ride Frequency Is Low:
  Same as the above, but on the opposite end of the spectrum. A lower frequency can be considered more comfortable. When this warning pops up, it implies that the springs might actually cause nausea due to an effect similar to sea sickness.
  
• Roll Angle Is High/Very High:
  Cars with softer springs tend to roll more, as well as cars set higher off the ground. The best way to reduce roll is with a sway bar, assuming you can't alter the ride height, which you might not want to do on certain cars either due to the target demographic, or the limits of the suspension itself. Stiffening the springs, as mentioned may help, but often not by much.

All cars have the five key stats, and four secondary stats that drivers will look at, each grouping having different base statistics, which are then modified by the modifying stats that go below them. Some buyers will look at specific stats, which are special subcategories.

Stats are calculated with key stats as a base, and then additional modifiers added or subtracted in separate groups.

Handling and Brakes, Drivetrain and Performance, Chassis, Suspension and Wheels, and lastly the Interior will all have separate modifier groups that will add or subtract from the base scores for the overall final result.

Evasion: Evasion is how much G force the car can pull at low speeds. As one would imagine, a high evasion stat lets the driver more effectively avoid road hazards.
Footprint: Generally, smaller cars can be considered easier to drive.
Control: How good are the brakes at low speed, and how well can the driver handle the power the engine produces? A car with better control is easier to drive.


Handling and Brakes
Assists: Generally refers to any form of traction aids the car may have. Having traction aids at all is good.
Steering: Will only show if you have power steering, or if there's a penalty due to lack of it. Power steering always makes a car more drivable, even if the car doesn't necessarily need it.
Brake Fade: Drivability brake fade, if it exists will hurt drivability, obviously.
Brake Quality: Better brake quality is always good for drivability (with some exceptions).
Assists Quality: Anything done with the quality slider for drivers aids will show here.
Brake Balance: Having imbalanced brakes will hurt drivability of the car. You don't for example want 300 size rear disc brakes with racing pads and six pistons, and only have a tiny drum in front. This appears to measure balance relative to tire grip, and the brake force on each axle. One axle locking and another not is bad, for example.
Terminal Oversteer: Low speed terminal oversteer is extremely detrimental to drivability.
Wheel Spin: Wheelspin harms drivability. A little bit is okay however.
Circle Test: How close to a 20 meter radius can the car keep when driven at low speed? If it can't do this without oversteering into the circle, or straying too far, it will be penalized slightly. If it can, it will be boosted slightly.
Brake Pad Type: What grade of brake pads are on the car? Metal grabby brakes? Spongy soft brakes? Drivable in between brakes?

Drivetrain and Performance
Torque Curve: How does the engine torque curve look like? A flat torque curve is generally easier to drive than a surging, near vertical torque curve.
Throttle Response: How responsive is the engine to requesting power from the driver. Higher response is almost always better.
Max Acceleration: Can the car accelerate in a reasonable period of time? If not, there will be a penalty.
Power to Weight: Is the engine underpowered for the car? This field is usually only used for penalties if the engine is in fact underpowered, with less than .025 power to weight ratio.
Drive Type: Generally penalizes RWD cars and 4x4 cars, since they are slightly harder to handle than a FWD car. Usually a minor penalty of 5%.
Torque Steer: Generally only applies to transverse FWD and AWD cars which output a lot of torque. Torque steer is what happens when the driveshaft is uneven in length on both sides of the car, as a result, the car will trend towards the side with the longer shaft under acceleration.
Gearbox: How much work goes into changing gears? Automatics generally won't apply a penalty here, while Manuals would.
Diff: What flavor of differential is installed? Different differentials can make the car easier or harder to drive.
Top Speed: Not quite as important as sportiness top speed, however cars which can't go fast can be considered less drivable, especially under highway conditions.

Suspension and Wheels
Suspension Tuning: A massive influence on how drivable the car is. Any normal suspension tune will be acceptable, in most cases, even if it leans sporty or comfortable.
Wheel Load: How weighed down are the tires compared to what they are rated to handle? Less load on the tires is generally more drivable, while edging close to the limit can be very undrivable.
Grip Reserves: How much extra grip is available when used for braking, some extra reserves are usually helpful. This usually means that the brakes won't lock the tires in wet conditions due to less grip.
Roll Angle: How far does the body tilt in a turn? Generally 4 to 6 degrees is drivable.
Suspension: What type of springs are being used, and does it help to drive the car easier?
Suspension Quality: How much work went into the suspension setup. More quality is always better.
Bottom Out: Bottoming out at all usually hurts everything on the car, stats and the chassis itself.
Cargo Tilt: Is there a risk of any cargo spilling over the side in a high speed turn? Generally cars, usually Trucks and Vans specifically, with lower roll angles run this risk.
Tires: Are the tires good to drive on? Sports compounds and up are generally harder for a normal driver to work with.
Driver Height: How high above the road does the driver sit? A higher seated position allows the driver to see more, and is overall better for drivability.

Cornering: How well does the car handle turns at high speed? High G force turns are key here.
Acceleration and Braking: How quickly can the car accelerate? Faster 0-100 times are key here going both ways.
Throttle Response: How fast can you get the engine to rev while the clutch is in?


Handling and Brakes
Agility: How well can the car handle low speed turns? Higher G force at low speed is better.
Electronic Stability: ESC, if it exists is always beneficial to sportiness.
Launch Control: Launch Control on top of ESC is amazing for sportiness.
Brake Quality: Better brake quality makes for better sportiness.
Assists Quality: Same holds true with drivers aids.
Cornering Gs: The maximum G force at high speed drives this stat. Anything above .7G is good, usually.
Brake Fade: Brake fade is hard to avoid on high performance sports cars. However, reducing it is critical.
Pad Type: Grabby, harder pads are better for sportiness.
Power Steering: Power steering removes the drivers ability to "feel" the road when driving, even if the system is high quality. Avoiding it if possible is great, but heavy cars literally can't be driven without power steering.
Circle Test: Same as the drivability circle test, but with a 200 meter circle, and much faster.

Drivetrain and Performance
Redline: How high can the car rev? Higher revving engines are sportier.
Diff: Most differentials help with sportiness to a degree that aren't full lockers.
Cylinders: 6 cylinders is optimal for not incurring a penalty, while not giving a bonus. More cylinders boosts sport, while less hurts it.
Torque Steer: Refer to drivability above. It's slightly less detrimental for sports cars.
Torque: How much peak torque the engine outputs. Higher is better.
Gear Ratio: Sports car drivers generally prefer tighter gear spacing, since it means you can keep the engine at higher power, even after going up a gear.
Loudness: Sports car drivers also like to be able to hear the engine of the car. Some interiors can reduce this.
Gearbox: Sports car drivers generally hate automatics and much prefer manuals, or other gearboxes which offer manual options.
Top Speed: Critical in determining how sporty the car is.
Power: Also critical for sportiness. A car with a less than .05 power to weight ratio will be heavily penalized for sportiness.

Chassis and Body
Total Height: Sportier cars generally run lower than other cars, and is preferred over a high riding car.
Drag: Less drag is overall better, hence Coupe cars are better than larger cars such as SUV's.
Chassis Quality: More work into the chassis types are better at pretty much everything.
Downforce: Downforce allows for less dangerous high speed steering, and it gives more of a feeling of the road. Downforce is sporty, lift isn't.
Chassis Stiffness: Stiffer chassis types are more predictable to drive than a wobbly chassis, which is why materials like AHS and Light AHS steel is rather good for sports cars.

Suspension and Wheels
Roll Test: A test to see how well the car performs. A car with around a 3 degree roll angle is the peak of sportiness.
Suspension Quality: Higher quality suspension is better at everything.
Tires: Is the tire some form of sports compound? If so, it's better for sportiness.
Suspension: Suspension choice matters for determining sportiness as well. Pushrod suspension is a notable example.

Interior
Seating: Single seat cars are very sporty, if extremely niche. Bench seats are not sporty generally.

Entertainment: How high quality is the entertainment system of the car? Fancy, brand new stuff, or barely a speaker?
Suspension: How high quality of a ride does the car have?
Interior: How comfortable are the seats?


Handling and Brakes
Spring Frequency: Lower (softer) spring frequency is comfortable, higher spring frequency is not.
Brake Quality: Again, higher quality brakes are generally better and more comfortable.
Steering: Power steering is generally comfortable compared to lack of it.
Brake Caliper: Different types of brake calipers have various degrees of comfort. Generally, more pistons on the caliper makes for smoother brake force application, which is comfortable.

Drivetrain and Performance
Gearbox: Automatics are much more comfortable for the driver than a manual gearbox.
Throttle Response: A relatively low throttle response is generally good for comfort of the car. Extremely low response is bad, and too high of response can be bad as well.
Torque: Reasonable torque is important for making a comfortable car. Lower torque is more comfortable than high torque.
Smoothness: Smoothness of the engine is rather important for comfort of the car. An engine which rattles around in the bay rattles the whole car and is uncomfortable.

Chassis and Body
Chassis Quality: A more worked on chassis is comfortable.
Chassis Stiffness: A stiffer chassis is generally more comfortable than a wobbly chassis.
Convertible: Soft top convertible cars have a comfort penalty of 8%, and hard tops have a comfort penalty of 4%.

Suspension and Tires
Suspension Options: Different suspension choices heavily influence the comfort of the car.
Suspension Tuning: Different suspension tuning will change comfort, sport and drivability of the car. Softer suspension is comfortable.
Tires: Different tire compounds are more or less comfortable. Medium compounds offer more comfort, and chunky offroad tires have penalty.
Tire Profile: High profile tires are rather comfortable, while low tire profiles are not.
Roll Test: A score assigned based on the roll angle of the car. 7 degrees appears to be the peak of what's good for comfort.
Sway Bars: Sway bars which are stiffer will generally be less comfortable.
Suspension Quality: High quality suspension is always better.
Bottom Out: Bottom out is massively uncomfortable.

Interior
Sound Insulation: Sound insulation is measured against the loudness of the engine and the interior grade of the car, with higher grade offering more insulation, save for Sport, which is specifically designed not to insulate the sound of the engine.
Interior Quality: The interior quality of the car makes for a more comfortable car, obviously.
Seating: Bench seats in the car will give a 5% penalty to comfort, per bench. Optional seats have another 5% penalty, which can also stack with the bench penalty if the optional seating is also a bench.
Entertainment Quality: Entertainment quality refers to the type of entertainment system installed. Earlier entertainment systems, such as early AM radios won't offer much boost to score, and in fact most will penalize it slightly. As time goes on, there will be greater score percents which will apply to new entertainment formats.
Passenger Volume: A more spacious car is comfortable, but this stat is hard to achieve without an extremely large car with minimal seats. Engine placement can also eat into the total passenger volume. Morphing the cabin to be bigger can bring this up.

Engine: How massive is the engine? How many pistons does it have? People always like big engines.
Footprint: Bigger cars are more prestigeous.
Interior: How high end is the interior of the car? Is it made of high quality material?


Handling and Brakes
Brakes: When carbon ceramics exist, they give a boost to prestige.

Drivetrain and Performance
Forced Induction: People like turbochargers and love superchargers. Small turbos give a small boost to prestige, and large turbos give more.
Gear Count: More gears in the gearbox is better for prestige, with 5 gears being enough to not incur a penalty, more offering more, less incurring a penalty.
Gearbox: The type of gearbox in the car will influence prestige. More advanced gearboxes for their time will boost prestige, such as a basic automatic on the '60s and dual clutch in the late '90s to 2000's. The basic automatic will harm prestige over time however, once the advanced automatic becomes available to everyone.
Drive Type: Front wheel drive is bad for prestige, rear wheel drive is fine, and all wheel drive is beneficial to prestige.
Top Speed: Fast cars have prestige, while slow cars don't. The bar for "what is fast" goes up over time.
Power: The more power the car produces, the more prestigeous it's considered to be.

Chassis and Body
Chassis Stiffness: A stiffer chassis is better for prestige.
Chassis Prestige: Different types of chassis materials and configurations have different prestige values. A carbon fiber monocoque is extremely fancy for example.
Panel Prestige: The panels of the car are also a large factor in determining prestige. Aluminum is highly coveted, and carbon fiber even more so. Fiberglass on the other hand is basically plastic, and not good for prestige.
Body Quality: Putting more work into the shell of the car is good for prestige.
Chassis Quality: Putting more work into the chassis is also good for prestige, but not as influential as working on the body.
Convertible: Convertibles are inherently more fancy, and have a higher prestige rating.

Suspension and Wheels
Rims: The material the rim is made of has some benefit for prestige. Mags offer 1.5%, alloy offers .5%, and carbon fibers offer 3%.
Suspension: Certain suspension types offer prestige. Pretty much everything that isn't a conventional spring is good for prestige.
Rim Diameter: Bigger rims are in general offer more prestige, though they can get a bit expensive if combined with a fancy rim type.

Interior
Interior Quality: Working on making a better interior adds prestige.
Seats: Bench seats are bad for prestige, and having optional rear seats also a negative, though the modifiers for an optional bench doesn't stack.
Entertainment Quality: Better entertainment systems will improve prestige, while worse will detriment it.

Safety: How modern are the actual safety systems in the car? Do you have airbags or not?
Weight: In a car versus car collision, who would win? Heavier cars are generally safer than light cars.
Footprint: Larger cars generally have more margin of error in the event something goes wrong for passenger safety.


Drivetrain and Performance
Engine Placement: If the engine is mounted in the front of the car, you get a straight 5% safety bonus.

Chassis and Body
Chassis Quality: A more thoroughly constructed chassis is safer than otherwise.
Convertible: Since convertibles don't really have an effective roof on the car, they are inherently less safe than other trims.
Chassis: The type of chassis chosen will influence safety. As covered earlier in the guide, Ladder frames are generally less safe than other choices.
Panels: Panel type is also a factor of how safe the car is. Fiberglass in particular is just awful at keeping people safe.
Safety Quality: Working to make the car safer can be a rather significant investment, but one that pays off a lot in terms of safety score.
Safety: What type of safety instruments are there in the car? Early safety techs will almost always cause a negative here, but that's to be expected.

Suspension and Wheels
Suspension Options: Air springs, active systems, and hydraulic springs are slightly more dangerous than a standard coil spring. Presumably due to the extra pressurized hydraulic fluid or air, which might possibly explode in an accident.

Interior/Other
Interior Quality: Higher class interiors are generally slightly safer than less great interiors.
Seats: Bench seats are slightly unsafe, since you can't get the same safety equipment to protect the middle passenger. Optional seats are extremely unsafe in general, for similar reasons.

Seats: How many people can you safely seat in the car?
Doors: How many ways can you get people/stuff in/out of the car?
Spaciousness: Do the passengers have room to move their legs, or have room for extra baggage?


Chassis and Body
Load Capacity: A car which can haul more is more practical.
Accessibility: A car which is at a good height to load passengers and cargo is also good for practicality. Too low and people have to bend over to load things. Too high, and it's hard to get in/out of the car.
Width/Height: Grouped together, because laziness, bigger cars are more practical in general.
Ground Clearance: A car set too close to the ground will be less practical if the car is actually loaded down.

Suspension and Wheels
Tires: Pretty much anything above medium compound tires are going to be less practical, since they aren't typically designed to carry loads. Hard and chunkies are slightly more useful for practicality since they can resist the wear of daily use better.

Load Capacity: How much can you load inside the car?
Size & Weight: How heavy is the vehicle, and how big is it? Will the chassis collapse if you put a fridge in it?
Towing Capacity: This stat is a bit weird, but can your car tow anything? Cars with high cargo capacity won't usually be able to tow much as a result of how the formula works currently.


Handling and Brakes
Brake Fade: Utility brake fade is exceptionally hard to avoid, without using supercar tier brakes. However, reducing it is essential.
Braking Versus Grip: Brakes need to be set a bit stronger than most other cars for utility purposes. Stronger brake force is essential to stop a moving, loaded cargo vehicle. The braking at max load percentage directly translates to here.

Drivetrain and Performance
Extra Cooling: Engines for utility trucks tend to be run hard to accelerate. Extra cooling is essential to keeping them running.
Gearbox: The type of gearbox in the car is important for utility. Generally, automatics are preferred.
Differential: Though not required, lockers are a nice feature to have on a utility vehicle. Electric LSD is nice, but is often too expensive to put into most forms of utility focused vehicle.
Power: More power is always helpful when hauling loads.
Power Distribution: As a general rule, utility vehicles should be rear wheel drive, as a majority of the weight will be on the back end of the car. If all wheel drive is used, significant preference will be for mostly rear end powered cars.
Gearing: Being weighed down means that cars will accelerate slower. This can be offset with wider gear spacing, which applies more power sooner. High gear ratios will usually outweigh any wheel spin penalties for utility vehicles.

Chassis and Body
Environmental Resistance: Ideally, you'd want a vehicle which won't rust on you immediately. A resistance rating of 45 seems to be the sweet spot for not being penalized here.

Ground Clearance: How high does the car sit above the ground? Higher cars are less likely to get stuck on rocks.
Tires: Can the tires handle dirt, or will they get shredded immediately?
Power Distribution: What type of drivetrain does the car have? Ideally it would be a 4x4 or AWD setup with power balanced to weight for an offroad vehicle.


Handling and Brakes
Braking at Low Load: How powerful are the brakes when the car is at minimum load? Better brake force is better overall for this stat, even if it goes over normal grip limits.
Stability: How stable is the car when going over uneven terrain? This usually is offset by the suspension tune favoring high vehicles, since a higher car will be a bit less stable.

Drivetrain and Performance
Differential: Manual lockers are almost a must for offroad cars. Open diffs are in general terrible for them. Viscous and Geared diffs do give some base score, but it's offset with the penalty using said diff has. Electric diff is nice, but won't give as great a bonus as a locker.
Torque Curve: A downward trending torque curve is generally preferred for an offroad vehicle.
Driver Aids: ESC and Traction Control are very useful for an offroad driving car, as one would assume.
Power to Weight: Higher power to weight ratios are generally preferred over a lack of it, mostly to power up hills and over rocks.
Gearbox: Manual gearboxes, and advanced automatics are preferred by offroad drivers. They generally don't like sequentials or dual clutches. Basic automatics are acceptable.
Low Gear Speed: The lower the cap for first gear is in terms of max speed, the better. This allows for faster power application, which can force the car out of tough spots.
4x4: Does the car have a transfer case? A 4x4 drivetrain is quite simply the best choice for an offroad driver.
Weight: An extremely heavy car is more likely to get bogged down in mud. Staying under a ton is usually beneficial if possible.

Chassis and Body
Panel Material: Variants of steel are the best panel types for an offroad vehicle to avoid this specific penalty. Aluminum doesn't handle dirt very well apparently, and even partial aluminium will give a penalty. Fiberglass and carbon fiber are even worse. The penalty for using these materials are usually offset significantly by environmental resistance bonuses however.
Undertray: It's almost always a good idea to install an offroad skidtray if you're shooting for an offroad type car.
Environmental Resistance: Offroad cars will be seeing a lot of dirt. If you can get the environmental resistance above 55, your'e not going to see a penalty.

Suspension and Wheels
Tire Offroad: Chunkies are the best tire type for an offroad driving car, however hard long life can work pretty well too, and medium compounds aren't completely terrible. Sports compounds will die if they touch rocks though.
Suspension Tuning: Soft springs and dampers are usually best for offroad vehicles.
Swaybar: The less stiff the swaybar on the car the better. It's okay to have "boaty" roll angles of nearly 8 degrees on offroad cars.
Rims: Stick to steel rims for offroad cars. Alloy and magnesium especially tend to corrode when in contact with dirt.
Spring Choice: This generally won't apply unless you choose hydraulic suspension, or active comfort. However, both of these choices are great for offroad cars, if the buyer can afford it.
Tire and Suspension Quality: Higher grade tires and better suspension handle dirt better.

The markets of automation is who you're trying to design a car to cater to. Each market has it's own subsections of what people want, sometimes favoring one thing over another, even though the market should, in theory be largely similar. I'll try an explain these markets dividing them into chunks, starting from the top of each row and going down from there.



The offroad markets "generally" are looking for a SUV, although Offroad Utility prefers the open tray of your typical Pickup. The main features of an offroader is a very high ride height, with usually solid axle coil suspension. Budget and standard markets favor a reasonably fuel efficient vehicle, while the premium markets favor a large engine over fuel economy.


I'm going to cover delivery vehicles in a large chunk here, since they all aim for essentially the same thing, which is cargo area. Light delivery being acceptable with smaller bodies, and heavy delivery favoring large bodies. Comfort basically is an afterthought on delivery vehicles, as is drivability to a degree. The main focus is a reliable, and reasonably fuel efficient box.


A typical pickup truck. Pickups focus largely on utility, and often mix in a bit with offroad cars, since quite a lot of characteristics are shared. Your typical utility truck should be well rounded, reasonably priced, and have a major focus on utility, including some extremely short gearing to put down the maximum amount of power possible. Heavy Utility trucks need to have a pure focus on hauling capacity, and a large engine, while typically throwing everything else out to achieve it.


Offroad Sport is a strange type of car. You want your Offroad Sport builds to be large, well balanced (overall) and have a very powerful engine in all fields. All Offroad Sport markets look at Drivability, Sportiness, Comfort, and Prestige, on top of all the engine power related stats, AND utility on top of that. Your "low end" offroad sport vehicle will typically be about as expensive as a typical family car.


The MPV market or, "Minivan" market. Generally follows the same trend as your typical family car, but specifically wants a minivan, at least 6 seats, and a good amount of cargo space on top.


Your typical passenger fleet car is an oddity, since they can be nearly any trim. In general they are larger vehicles, with an extremely strong focus on practicality, and reliability. Although the tooltip says that the car should be comfortable, I've found that standard (and sometimes basic) interiors with a basic entertainment system leads to a more desirable car.


Your typical Family Utility car can be basically any trim you can think of. The key thing being that the car needs to have at least 5 seats. Practicality is still a huge part of this market, as well as drivability and comfort. As you'd assume based on the market, they also care about utility, and torque.

A city car needs to be small, extremely simple to drive, and reasonably fuel efficient, especially when aiming for the City Eco market. Ideally it'd be a hatchback too, but sedans are viable choices too. It is extremely easy to over budget when designing a city car. Most city cars will have an I3, or I4 engine, sometimes with an eco turbo.


Quite similar to a City car, but designed for long distance highway travel over short distance. Commuter cars generally have an even distribution of focus between drivability, safety, fuel economy, and reliability. They also should have at least four seats, and ideally are sedans.


Family cars are generally larger, drivable, and extremely safe models of cars, with at minumum five seats in the car. The family market is pretty much always the largest market in the campaign, and can deliver good income if you keep costs low.


Similar to the family market, but with a much higher focus on sportiness, as well as specifically favoring cornering, as well as power. Family Sport cars are acceptable with 4 seats.


A fun car is a reasonable car for everyday use, so it should be reasonably small, nimble, quick and a bit sporty. They can be a variety of trims, and need some degree of creature comfort.


A baby muscle car. Your typical pony car needs to be reasonably cheap, easy to produce, and still has a good size engine behind it. It's also got to be relatively practical so, it's not unusual to see a smaller city car on the outside, with a large engine on the inside to be considered a pony car. Coupes are preferred however.


The light sport category is a sports car category which is looking for a powerful car, which is good at cornering, and has decent throttle response while also being lightweight, and a bit fancy.


The muscle car is basically built entirely around the engine. A huge engine, as well as high torque and power are key here. Generally some prestige helps here as well. Basically nothing else is cared about. Steering is overrated anyways.


A track car is essentially a light sports car, but with basically everything stripped out of it, to save weight. The track car market is one of the few markets that will buy a single seater. The main focus of a track car is cornering, and braking, with sportiness being the key to everything.


A big, fancy sports car. Easy to drive, sporty, comfortable, and with a high rev limit and power.


High end, high power convertible car. The only real difference here compared to Sport is the trim, where this market caters to.


Unreasonably luxurious, and with an extremely powerful engine match this category pretty well. These cars are essentially hybrids of Track, Sport, and Luxury cars.


A typical convertible car is focused almost exclusively on comfort and prestige. Higher end models also have more of a focus on engine smoothness, and it's not uncommon to see extremely complex, smooth running engines here.


Pretty much a cross between a muscle car, and a premium car. All driving stats are viewed equally, the engine needs to have the smoothness of a premium/convertible car, as well as a lot of power and high redline when the driver wants it.


Your typical premium car almost exactly meets the demographic requirement for an equal tier convertible, except without the collapsing roof. The only real difference here is that it seems safety is prioritized more.

Gasmea is more or less supposed to be a country following along the lines of the US, France and UK. Car buyers tend to prefer larger than average cars, and have a very high desire for a prestiegous, comfortable, and safe car. The typical Gasmean will strongly prefer an automatic transmission over other forms of transmission, since they generally go hand in hand with the Gasmean preference for comfort and drivability. The average Gasmean is relatively wealthy, due to having the largest economy in the world of Automation, and can usually afford extra features. Gasmea early on into the game will not have displacement taxes but will eventually institute a few very generous size limits.

The average Hetvesian generally doesn't care about any specifics compared to other countries, except for a massive hard on for safety in particular, and fuel economy. Hetvesia is somewhat an alternative central Europe series of countries, such as Switzerland, Austria, South Western Germany and the like. Hetvesians tend to be okay with most cars that would normally be considered slightly subpar, as long as the car is relatively small for their role, has decent fuel economy, and is very safe. Slightly below average wages compared to Gasmea, but they can still afford most cars.

More or less an alternative Italy, with a bit of Japan mixed in. Fruinians are obsessive environmentalists, as well as major sports fans. They don't care about much, save for sportiness, and fuel economy and practicality of the cars they buy. It's not entirely unusual for them to stick with manual transmission cars over an automatic, even if everything else about the car is the same. The average wage is slightly lower than Gasmea, but they can still afford a few features. Fruinia starts and keeps a very strict set of displacement taxes making engines over 1L unviable a lot of the time.

Archana is best described as an Eastern Bloc country shortly after the Second World War. Archanans significantly prefer offroad/utility cars, and they want their cars to be comfortable. The main issue with Archana is the fact that the average Archanan simply can't afford a car built to the same standards of other countries, as on average they have 40 percent the available money of a Gasmean. The budget categories have essentially no money to speak of, and the normal "budget car" of another country may often be considered to be a "normal" or even "premium" category in Archana. It's not unusual at all for a budget Fruinian sports car to be considered a Hypercar in Archana, for example. Archana also pretty much never acquires any fuel grade over Regular, and don't have any safety standards, at all, until 1990.

Cars in Dalluha are status symbols over everything else. Dalluha is largely considered to be the Shiekdoms of Arabia when compared to the world we live in. The average Dalluhan wants their car to be huge, fancy, and practical without really caring about being able to drive the car safely, or fast. They also don't seem to care much about safety features, and it's entirely possible to sell cars into Dalluha without any safety features at all, or the bare minimum for a very long time. The average buyer can generally afford cars on the same line as a Fruinian, while the wealthier markets can afford far more than a Gasmean, but the economy is tiny, and odds are there won't be too many buyers.

There's a few terms which aren't very well explained without having to look them up, so i'm going to try and put everything you'd probably have a question about here. For the sake of completeness, i'll also add in stuff we've gone over already as well.

• Model: The base chassis, and it's size, which determines what type of shell/trim can be used.
  
• Trim: The specific setup for the body type in particular.
  
• Wheel Base: How far apart the axles are from each other.
  
• Track Width: How wide the axles are, before rim offset.
  
• Family: The base configuration of an engine, such as it's block type and valves.
  
• Variant: A variant of the family of engine. Can have a variety of changes, including sizing and fuel system types for example.
  
• Fill Factor: How much space in the engine bay the engine itself takes up. A higher fill factor requires more time to figure out where to put everything else, and increases engineering time, and service costs.
  
• Oversquare: Bore bigger than stroke.
  
• Undersquare: Stroke bigger than bore.
  
• Displacement: How much fuel in terms of volume the engine can hold assuming all piston chambers are filled. This is measured in CC, or cubic centimeters, or in the US, cubic inches usually.
  
• Bore: How wide the piston chambers are.
  
• Stroke: How tall the piston chamber is, measured from intake valve to the lowest point the piston can go in a cycle.
  
• Bottom End: Piston, and crank assembly.
  
• Top End: The valve system, along with the camshaft(s).
  
• Octane: A measure of a fuels resistance to knocking, and a measure of how efficiently the fuel is being used. Ideally, a car should use all octane, but not exceed it.
  
• Knocking: A knock, or "ping" is caused when some of the fuel preignites before it's supposed to in an ignition cycle. Any knock at all is harmful to the efficiency of the engine.
  
• Valve Float: Valve float occurs when the valves are unable to completely close in an ignition cycle, usually due to high RPM. This results in the valves "jumping" the cam, as a result of momentum. This is usually very detrimental to the longevity of the valves, and engine as a whole.
  
• RPM: Revolutions Per Minute. This is how quickly the crank makes a full 360 degree rotation while running. Higher RPM ultimately delivers more power assuming torque remains the same or increases.
  
• Scavenging: Refers to exhaust pulses from each piston "lining up" and helping to pull exhaust from the most recently emptied piston chamber. A good exhaust ideally scavenges every last bit of exhaust out of the piston chambers before the exhaust valve closes.
  
• Overdrive: Can mean two things. An overdrive gear is technically any gear which has a ratio of greater than 1:1 (.99:1 is an overdrive gear, if just barely). Overdrive can also imply a final gear which is intended to be used near peak speed to run the engine at lower RPM, and save fuel.
  
• Final Drive: The final ratio of teeth of the last gear (not numerically, but physically, the last gear that actually spins the tires) in the assembly before the tires are turned.
  
• Tire Profile: Can also be referred to as the tire aspect ratio. A measure of how large the sidewalls are relative to the tread of the tire.
  
• Rim Offset: A value for how far the tires are pushed out relative to the normal end of the axles. Rim offset is often used to ensure stability in cars which have tire staggering.
  
• Tire Staggering: Essentially, any set of non equal width tires can be considered staggered.
  
• Terminal Oversteer: Basically, the car can't be driven at any speed without losing the back end of the car (spinning out). Cars with terminal oversteer are basically deathtraps.
  
• Brake Fade: There are three categories of brake fade in automation, and they all refer to how much the brake pad burns off it's effectiveness when braking. Brake fade itself is caused by heat saturation of the braking medium. Brakes turn motion into friction/heat to stop a car, however once the brake heats up, it's harder to add even more heat to slow down further, hence brakes will "fade" or become ineffective if overheated.
  
• Drivability Brake Fade: How much the brakes fade when going from 100 km/h to 0.
  
• Sportiness Brake Fade: How much the brakes fade when going from top speed to 0.
  
• Utility Brake Fade: Similar to sportiness fade, but measured with maximum cargo capacity.

• Try to predict how large of a factory you need when building your car. Factory costs won't/can't be predicted by the designer, so you should keep that in mind when producing your car.
  
• Micro factories might seem unviable but are extremely cheap to run and retool and staff for. They are excellent for super high end low volume trims like Luxury Premium, GT Premium and Hypercars.
  
• Tiny factories are best used to build limited production cars, such as high end Luxury cars and GT cars.
  
• Small factories are usually best with sports cars, and premium boats and entering the family premium section in more wealthy markets.
  
• Medium factories are good for introductory level mass produced cars, such as premium family cars, and other fancier premium trims in general without steel presses. With steel presses, this can get you off the ground to make thousands of cars per month and can get you into the general mass market, such as the standard Family segment.
  
• Large factories tend to be expensive to startup with, but can lead to vastly reduced costs for budget car types. They also have access to every factory addon in the game once unlocked.
  
• Huge factories tend to be insanely expensive to work with and change, but lead to insane output, as well as insanely cheap cars. This makes them great for super cheap budget cars, or commercial type cars such as delivery/fleet cars.
  
• Smaller factories really don't like to be automated, and large factories need to be automated in order to keep a decent production level going.
  
• Production flags are weighted against the automation level of a factory, and engineering tooling expectancy. A single No Mass Production flag in a fully automated huge factory will cut efficiency by 25%. A single No Mass Production flag in a fully manual tiny factory will do next to nothing.
  
• More automation will always make the price per car go down, even if it eats into overall production efficiency due to less staff requirements.
  
• Different countries have different wages, and different tax laws.

It's very likely I've gotten something totally wrong in the guide somewhere along the way. I try my best to be accurate, but sometimes i'm not. If you find anything totally wrong, let me know in the comments. That way I can fix the issue.