Detroit DD15 6 Cylinder 14.8 L Ultra Low Sulfur Diesel 505 hp Engine, Requires Diesel Exhaust Fluid, Engine Brake, Detroit DT12-1750-OH 12-Speed Automated Transmission, 13300 lb Front Axle, 40000 lb Rears, Detroit DA-RT-40.0-4S Drive Axles, 3.08:1 Axle Ratio, 53300 lb GVWR, Air Ride Cab, 82 in Mid Roof Sleeper Cab, Bunk Beds, Aluminum Wheels, 295/75R22.5, Airliner Air Ride Suspension, 240 in Wheelbase, Air Sliding 5th Wheel, Dual Fuel Tanks