i talked to some guy with a 12" lift with 40s on a 05 f-150 and he claimed to get 12mpg...i doubt that tho he prolly got more like 2mpg haha, but i have heard switching out the gearing for a lower gear will buy you quite a few extra MPGs, im thinking of moving up to a 4.88 because it pretty much covers tire sizes 35-44 and the biggest i would ever go but prolly wont is 44s...............that was completely off subject *slaps self*