I haul an 18ft daily with 2 Dixie Choppers and a 34in walk-behind 6 days a week. I haul a big tractor w a bush hog once a month for a couple of properties. I am getting 5mpg hauling my set up as of right now and have to fill up 2 to 3 times a week. I am hoping if I go to a another gas truck I can get at least 12mpg, can this be done with the set up I haul right now? I love the gas cause my mowers all run of gas and don't have to use two pumps to fill up the truck and mowers if I were to go to a diesel truck. But then again I love the power of the diesel, I use a duramax diesel for a week and got 18mpg hauling my 18ft trailer and 2 choppers and a walk behind.Do you guys think it is worth for me to up grade to a diesel? I can get a 99 ford f-350 XLT super cab short bed 4x4 7.3 auto w/ 148,473 miles for $10,000. Or I can get a 2004 Ford f-250 XL regular cab 4x4 6.8 auto w/ 31,000 miles for $12,000.