Cummins ISX15 6 Cylinder 12.8 L Ultra Low Sulfur Diesel 450 hp Engine, Engine Brake, Eaton Fuller 10-Speed Manual Transmission, 12000 lb Front Axle, 40000 lb Rears, 3.50:1 Axle Ratio, 56000 lb GVWR, Air Ride Cab, 44 in Mid Roof Sleeper Cab, Aluminum Outer Wheels, 295/75R22.5 Front Tires, 295/75R22.5 Rear Tires, Air Ride Suspension, Air Sliding 5th Wheel, Dual Fuel Tanks