I have owned a dodge Cummings (04) and a ford 7.3 (01) so my information is somewhat dated. I had a 6-speed in the dodge and an auto in the ford. I would get 20-21 in the dodge with 35's if I stayed under 72 mph. I loved that truck and hate I sold it. In my opinion it was better than my ford. But my company gives me a nice truck so I no longer need a nice personal ride.

All of our company trucks are chevys and electrical problems and front end problems are pretty common. They never seem to stay aligned very long