GMC Sierra Z71 2015 Automatic Gasoline mileage: 300 KM or more 4WD GMC Sierra Z71 2015 Full Option For Sale Automatic Transmission Gasoline Mileage: 300 GMC Sierra model 2015, clean body, no paint or bodywork, only a minor adjustment near the rear left tire, the size of a palm. Mileage 309 km Clean mechanics, double gear, engine, beginning of valve stem seals. Rear bumper has been changed.