Okay here is my understanding about efficiencies in an internal combustion engine...
You've got stored energy in the large molecules of petrol. This gets burned in hopes of extracting kinetic energy, but a lot of it gets converted into thermal energy (waste).
So why is that a hot engine will be more efficient, especially if that heat is there in the first place because of waste? Is it because the heat allows the fuel to vaporize more completely?
Also, if one was to make cylinders, pistons, and other engine components out of some material with a higher thermal resistance than is currently in place, would engine efficiency increase?
Am I way off base here?