“Normal” mode is similiar to most other non-simulator games with vehicle damage, e.g. GTA or Flatout.
Your car can take damage and will get totaled after taking too much damage, but it’s much more resilient to damage as it would be in real life; you’ll rarely wreck from a single crash and can hit a wall head-on like 5-10 times before your car’s wrecked (depending on the car, armor and speed of course).
Wheels can still break off, but it requires a lot of force so it is very rare for it to happen.
Damage to car components (engine, transmission, brakes, suspension) won’t affect the car’s handling/performance as much.

This damage mode also has “attacker’s advantage” enabled, meaning that when one car rams another, the “victim” will take more damage than the “attacker”. (Of course armor and car weight matters as well, it's not like you'll be able to wreck a school bus using a lawnmower or something).

A Rocket with stock armor hitting a wall at about 120 KM/H in "Normal" damage mode.

“Realistic” mode is, as the name implies, more realistic (although still not 100% true-to-real life).
Your car could easily get wrecked in a single crash or hitting a wall head-on once, wheels can break off quite easily and components getting damaged has a stronger effect on performance/handling.

Does not have "attacker's advantage".

A Rocket with stock armor hitting a wall at about 120 KM/H in "Realistic" damage mode.

“Intense” mode is basically somewhere between "Normal" and "Realistic" mode, not sure what else to say about it. Everything is more fragile than in "Normal" mode, but significantly stronger than in "Realistic" mode.

Has "attacker's advantage" enabled.

A Rocket with stock armor hitting a wall at about 120 KM/H in "Intense" damage mode.

This is basically the same damage mode as the tech demo for Wreckfest (then still called "Next Car Game") had back in 2013.

In this damage mode there are no health bars; you can only get wrecked by losing 2 wheels on the same axle (so either both front wheels or both rear wheels); everything else is survivable.
Visually the damage is even more extreme than in "Realistic" mode; cars deform and break apart much easier, and even parts that aren't deformable in other damage modes (such as the engine block) can be deformed in Extreme damage mode.

Does not have "attacker's advantage".


A Rocket with stock armor hitting a wall at about 120 KM/H in "Extreme" damage mode.