I could be mistaken, but your engine burns like 95% + of the fuel that goes into the cylinder. Really not much room for improvement in that part of the equation. People try to baffle with B$ when they claim that engines are only 30% efficient....well they are, but that doesn't have to do with the fuel burning, it is the pumping, thermal, and friction loses that cause that. But they make you think it's only 30% of the fuel being burned so if you improve combustion you'll see an improvement in MPG's, Power, cleaner emmissions, and your love life.
I conclude with:
