Maybe the idea of doing what GM did where half the cylinders can be killed when the car is at cruising speeds. Also, the ability to add a gyroscope that can tell the car to turn off when going down a hill to save gas (also what GM did). I can probably find more later, but this’ll do for now. 
Maybe eventually, but the last thing we need right now is MORE choices in the engine designer 
Sounds great! I’m not expecting it anytime soon, just a nice finishing touch type of idea.
I think GM also added an air pump to the exaust for a jeep or suv to lower emissions.