When I was looking at the options when I was considering changing my coach from gas to diesel, I looked and the torque ranges of the engines as well as the torque amount and the weight of the engine. The torque band for the Ford Powerstroke was much narrower than that of the GM Duramax. The Duramax power band is from 1600 rpm all the way to about 3000 rpm. That is a much wider torque band and makes the driving characteristics much better. With my 14,500 lb coach I can climb a 6% grade at 65 mph. But due to who is making the frames, etc. there are virtually no Duramax powered motor homes.