hello everybody first time to post thank you for the forum. have f-250 1996 7.3 turbo stock truck dont drive it hard 65mph easy around town will pull 24ft pontoon every now an then best mpg has been 8 to 10mpg .i bought truck used from old man who pulled camping trailer with it.has 117,000 on it and the only mod is no converter or muffler has a new turbo and waste gate unhooked.other people i have talked to say they get 20mpg from there 7.3 what could be wrong.truck has 4.10 gears.and could any one tell me what size my front an back fuel tanks are.