GMC Sierra 2500HD 2008 Automatic Gasoline mileage: 300 KM or more 4WD Peace be upon you. I have an HD2008. Mileage 490. Its affairs are good and it does not complain of anything. The floor is good. Its mechanical affairs are good. New tires. 4WD is good. The car is programmed and has a Magnaflow muffler. The car needs some minor, non-essential things, and it's negotiable for a serious buyer. For sale or trade.