Detroit DD13 6 Cylinder 12.8 L Diesel 500 hp Engine, 2015 US EPA Label, CARB Compliant, Requires Diesel Exhaust Fluid, Engine Brake, Detroit DT12-OB-1550 12-Speed Automatic Transmission, Differential Lock, 12000 lb Front Axle, 40000 lb Rears, 3.25:1 Axle Ratio, 52000.0 lb GVWR, Aluminum Wheels, 11R22.5, Airliner Air Ride Suspension, 178 in Wheelbase, Air Sliding 5th Wheel, Dual Fuel Tanks