Troy, irrelevant analogies to cars aren't helpful and just confuse the issue when audio technology is being discussed. The setting on the volume control(85% or whatever)isn't directly measuring the amount of power which is being used and wouldn't necessarily change one bit when an amplifier with a higher max was substituted. The actual use at a given instant at that setting might be close to zero(if the program material is quiet at that point)or might be 100% if an unusually high peak was occurring. It isn't something which should be a matter of concern.
