You posted while I was typing, so I will add one more point, now that I see what you will be towing. My son picked up a beautifully GMC Denali last year to haul his new 24ft enclosed race car trailer. I went out to Ohio and picked it up for him with my 02 Ram diesel dually, drove the 9 hrs back like it wasn't there. Now his 2500 short bed with the big 6.2L gasser hooks up to it for the 1st time, goes to the drag strip, about 70 miles away highway, with some substantial hills and mountains .... he hated it. He was so disappointed, he just traded it in for a brandy new diesel GMC ... see, he's driven my old Ram diesel many times pulling my 32ft race car trailer, the trailer weighing in somewhere around 12,000lbs ... that's when you find out the difference! Until you actually have the opportunity to pull with a diesel, you'll never know.