Doc, you're spot on, but haven't really offered any insight towards an answer. As a retired ME I certainly understand the principles of physics, etc., but thought someone might have some data that they would share that might help develop a curved/straight line relationship between crank HP and wheel HP.
Please don't take me wrong, I'm not trying to be a smart a$$. I just have found over my 40+ years of working that very few relationships are a straight line, but then again, my work experience was not in the automotive field. Just trying to better understand (if possible) my new toy.