Originally Posted By: Shannow
The sum of differences then points to only a single factor remaining...losses due to increased engine (and transmission) speed.
That part I get, but I'm still wondering how one would calculate the work in this case. Am I correct in that one can look at it from different frames of reference and different coordinate systems? The work done on the car as an object being moved over a displacement is clear, but the reason I am waffling around the engine is because there is extra friction, and more piston miles, as it were, so more work.
And as you've mentioned, the friction is significantly higher at 4,000 rpm than at 1,800 rpm. Of course, if it wasn't higher, it wouldn't use more fuel in the first place, at least once you got it going.
The sum of differences then points to only a single factor remaining...losses due to increased engine (and transmission) speed.
That part I get, but I'm still wondering how one would calculate the work in this case. Am I correct in that one can look at it from different frames of reference and different coordinate systems? The work done on the car as an object being moved over a displacement is clear, but the reason I am waffling around the engine is because there is extra friction, and more piston miles, as it were, so more work.
And as you've mentioned, the friction is significantly higher at 4,000 rpm than at 1,800 rpm. Of course, if it wasn't higher, it wouldn't use more fuel in the first place, at least once you got it going.