Crank vs. rear wheel

I kind of get where DGC is coming from - so I'll ask a question.....

Are the "gross to SAE " losses of 16% reasonable?
not sure what you mean but the diference between NET and GROSS hp is around 5% for any engine prior to 1972. if your using it as a bases for comparison is 5% loss for accesories + 16-18% loss for powertrain. 21-23% loss total when comparing pre- 1972 horsepower to the ground figures.