I recall reading here (can't remember who posted it) that companies that use diesels in truck and heavy equipment do their maintenance by hours of run time and by gallons of fuel consumed- because inorder to make power, you burn fuel, and to make more power, basically you burn more fuel. That also takes more air, and cooling of the intake charge air, and in turn getting rid of all the waste heat that isn't turned into power.... but it seems like essentially to make more horsepower, you have to burn more fuel. Is that true? At least it makes sense to me.