I have a 2500 short WB gas engine. I towed my race car yesterday and everything went great but when climbing a steep mountain I used 4th gear, it pulled at 60 mph at pretty much 5 grand. The wife thought it was pulling at to high a rpm but it seemed okay to me and the engine heat gauge ran at normal position the entire time. I guess my question what speed should I climb a hill at and what gear is best? Thanks guys. I'm towing a Fiat Abarth 500 with a 13 foot open trailer.