I understand the concerns of rising fuel prices (paid $4.65 last night in Camarillo, CA). However, we purchased trucks, not 4-cylinder scooters to drive around. Trucks get worse mileage, period. My mileage dropped w/ the Range control, Pedal Commander, leveled, valence removed, Cold Air Intake, auto-stop bypassed, and 275/65r20 Falken Wildpeaks. All of this on a 5.3 v8. I had the same engine on my old '08 Yukon in which I sold to my mechanic after 178K. His wife now drives it. I would ask all who have the issues what type of driving are you doing/what are you hauling? However, I can still make Vegas on one (1) tank of gas. Enjoy your truck. Cheers.