GMC Sierra 2002 Automatic Gasoline mileage: 1 KM Peace be upon you. I have a GMC Sierra, converted 2006. The engine has been changed and, ماشالله (Masha'Allah), it's very quiet. The gearbox is perfectly fine. The differential is perfectly fine. It has driven 400 and some change. It has a muffler and exhaust outlets. It has a lowering kit. The tires are almost new. The interior is very clean. It has been offered 23. We ask God for more 👍🏻