2014 Ultimate 1 Ton Challenge results

I have thought a bit about why a chassis dyno might read higher horsepower numbers in higher gears and have come up with what I think is a logical explanation: When power is transfered from the vehical tires to the chasis dyno's rollers, the torque exerted on the tiny contact patch distorts the tire. This distortion of the tire sidewall cosumes power. Running the truck in a higher gear would reduce the torque and therefore the distortion and power loss at the tire/roller contact point. The inertia type chasis dyno numbers are probably more valuable to dragsters interested in a 15 second run down the track. The conditions associated with a truck pulling a loaded trailer up a hill might be hard to duplicate on an inertia based chasis dyno.