yeah regular cab. My mpg went to like 20/21 when I kept my foot out of it. I took out ALL torque management and got the most aggresive tune I could get with the 4.3. Only reason was because the 4.3 doesnt really put out as much power to hurt the transmission. The 4.3 does have some power. But your gonna laugh in the face of the 4.3 power when you ride in a boosted application or a NA starting with the 5.3