I have read this test, and its so far removed from a scientific test, its hard to believe anything about it. For one, was any weather data adjusted from one test run to another? This entire test relied on the power output of the engine, which would vary from day to day, morning to afternoon. I am amazed that someone went to that much effort for unreliable results.

A real test would be just the rear, measure the bearing pre load, then measure the force (load cell on the pinion) it takes to lift a weight placed on one axle. Subtract the bearing preload and compare that effort to another rear. And make sure temps are all the same as well.