GMC Sierra SLE 2018 Automatic Gasoline mileage: 282 KM 4WD The car has Bilstein shocks, engine internals are guaranteed from disassembly, original lifters, and the transmission has a new torque converter. It has a Max Power cat-back exhaust with a bypass valve, X-Force headers, a Volant filter, and achieved good horsepower on a dyno tuned by Tariq Al-Tamimi. It also has a bedliner.