GMC Sierra SLE 2011 Automatic Gasoline mileage: 300 KM or more Sierra 2011 without double (4x4). For sale as parts or whole, needs engine swap. The car's mileage is approximately 468,000. The car is running. Whether you want it whole or for parts, it's all the same. 8-cylinder engine is sound. 4-speed transmission is sound. Differential is sound.