Mine has 4.56 gears, and Falken Wildpeak 33' x 12.50", with somewhere around 3" of lift. I'm getting about 16mpg around here, but on the highway, if I keep it below 70, I get around 18....oh, and I'm running a 6.0 LS (LQ4) with a 4l60e transmission. That could have some bearing on the mileage. I...