So I boutght a 26 foot tt last week and had a 2014 ram 1500 express 5.7 which was rated at 8500lbs pulling. Needless to say it was terrible. The truck got 5 mpg and could not go faster than 60 mph. I even bought the 4 point sway wdh and so decided to buy the diesel. Maybe a little over kill for a 6500lbs camper but I couldn't be happier.