I had a 6.0 fuel mileage is terrible they are gas hogs towing got around 7 mpg not towing around 12 unhooked but pulled trailer fine but engine really had to work You might want to consider a 2500 or 3500 with a duramax If your buying a truck spend a little more for a truck that will do the job We did the very thing your doing bought a 1500 hd thinking it would be fine but was very unhappy Went and bought a 2500 diesel will never go back as long as we own a camper wish we would have bought a 3500 dually Fuels a little more but the benefits are worth it for us anyway no limitations on trailers Good luck