I have an '04 DRW F-350 Crew Cab. I've been getting 12-16mpg in the city, no extra weight. I have a 5th wheel toy hauler that according to the sticker weighs just under 10k full of gas and water, so let's say under 12k with the dirt bike and quad, plus clothes, etc. Towing on mostly flat roads, I get around 7.5mpg. I have a 4.10 rear end. I've been told that I should be getting better gas mileage, but not by anyone who has anthing close to what I have. Comments?