GMC Sierra AT4 2021 Automatic Gasoline mileage: 210 KM 4WD Peace be upon you. For sale: GMC Sierra AT4 2021, black. The interior is like new, clean. Mileage is around 215. Gulf specs from the UAE, and the color came like this from the UAE. I am the first owner in Saudi Arabia. It has some additions for the serious buyer. There is damage to the right side: door + post and fender. Its differentials, chassis, engine, and gearbox are fine. And the differential lock is unlocked.