Put 4.56's in it, the mileage will come up 2-3 MPG. Literally. My coworker running the big 37 M/T's is back up to 17+ and was only getting 13.5-14 with the 3.45's. Change the gears, do the reprogramming for the tires and gears, let the transmission learn. BIG difference. Plus it flat out drives better.Yes. A lift and 35s will do that to a Jeep.