Z71 2021 Automatic Gasoline mileage: 94 KM 4WD For sale, dark red Silverado, model 2021, Trail Boss. Mileage 94, can be increased. Engine and transmission are guaranteed. The body has the lower part of the right front fender repainted. Additions: It has Profender control arms. Sports air filter. 40,000 BTU transmission cooler. The vehicle is for sale to the highest bidder.