Fuel mileage mods and alternative fuels

i have a 01 cummins ho 6sp. 3.55 ratio 4x4.quad cab. i was getting 17.5 mpg. i have a quadzilla adrenaline box on it.it is rated at 180rwhp and 420 lbs tq at wheels, air dog fuel preperator, 5 in exhaust, k & n cold air intake, hx 40 turbo, 100 hp edge jammer injectors, i am getting around 21mpg now. this empty. i pulled our gooseneck trailer with 15 calves weighing 500-600 lbs each and got 19.3.alot of your problem is the 4.10 gears. I can get you the jammer injectors for $260. then they need to be pop tested for another $65. and they are ready to go..seem to work pretty good. i am hitting about 1050lbs of torque at the rear wheels right now.