Having read all the above post, they all hold some truth depending on your preference and experience (good or bad) with your diesel or gasser. IMHO, the newer gassers with all the technological advances can equal the towing capabilities of a diesel to a point. In my case, my older
(2002 Chev. 1500HD 6.0 gasser, 4 speed A/T) handled the load
with ease, but towing mileage was in the 7-8 mpg range. And, I could rarely use overdrive or cruise control without it "searching" for a gear. Now, my newer 2011 Dodge 2500 HD w/6.7 Cummins TD w/6 speed A/T pulls the same TT with much less effort and towing mileage is in the 12.7-13.2 mpg range. But, I guess with the difference between gas and diesel fuel prices, the cost per trip is probably a wash. In my case, it came down to peace of mind and we also plan on upgrading to a 5er in the near future and needed to get the TV first (and paid off) before taking on the expense of a new 5er.