me and my friend are having an arguement about this. I say that because frictional force is less than or equal to the coefficient of friction times the normal force, and that neither the coefficient of friction nor the normal force can be increased while an engine is running(until it's oil is overheated or too cold), then frictional force remains constant in a running engine. While he says that "since more heat is generated at higher rpms than lower rpms, then it must take more power (power = work/time) to increase rpms at higher rpms rather than lower rpms." But I'm pretty sure, not positive, that this doesnt mean more power has actually been lost. who is right in this arguement?