Hi Oggers.
I thought of an even better example to explain it. Compare a gasoline to a diesel (low compression to high compression).
Diesel fuel has 11% more energy by volume than gasoline.
A diesel engine is approximately 30-35% more efficient at the same RPM and fuel flow. Let's assume 30%.
So that's 30% more power from 11% better fuel. If you take the 11% off to even the playing field of fuel energy density, that's 19% more efficient.
Are you trying to tell me that 19% effciency gain comes about solely because of more complete combustion and "mixing"?
Going on your theory, that means 19% of the fuel in a gasoline engine must not be combusting.
I guarantee if your gasoline engine was putting 19% of it's gasoline down the exhaust, your typical cat converter wouldn't last more than a week.
Unfortunately, the fallacy that higher compression engines gain their efficiency from more complete combustion will continue for years to come.
More energy is transferred to useful work because less heat is wasted heating the fluid. It's that simple.