This is a very cool mod. I'm trying to move away from transporting resources long distances by using electric steel mills and solar power. This helps by providing the small amount of coal required by the steel mill. Now if only I could get some raw oil from wood and/or crops.

They're balanced to be usable in the game. You can alter the values if you want to but I think these are ok as they are, I don't want to make them so inefficient that they aren't worth using. They're not meant as an alternative to the coal industry, more supplemental or for supplying either a small brickworks or a small heating plant and for early game or hard mode starters.
As for having them produce a small amount of bitumen, it's not a bad idea and there are such things as tar kilns but they are different to these and they would require remodelling as well as re-scripting, which is very time consuming. I am working on other projects right now and don't have the time. I will give it some consideration and may make one at some point but I have several projects on the go and a long list of other stuff I want to make too, and only one pair of hands!

lol, been busy with other stuff :-D

Took you long enough with this one.

Thanks, superb!