Tough decision! I have been towing with a motor home for several years. The last 2 have been gas. I presently have a 2009 Daybreak, 36', with the Ford triton. It pulls just fine, just need to take it easy on the real steep stuff both up and down. Monarch pass is one of Colorado's worst. I usually stay in 2nd gear. A couple things to consider with the diesel: Is the extra money worth the extra towing power? Is the smell and crap all over the tow rig worth the trouble? I will agree the gas mileage is much better.....but then you have to take out a second mortgage each time you pull into the pump. Oil changes and service are out of site. And I'm not a big fan of air brakes. If money isn't a concern then I would go diesel!