Cummins ISX 6 Cylinder Ultra Low Sulfur Diesel 500 hp Engine, Air Conditioner, Cruise Control, Engine Brake, Eaton Fuller RTLO 18913A 13-Speed Manual Transmission, 12500 lb Front Axle, 40000 lb Rears, Meritor MT-40-14X Drive Axles, 3.55:1 Axle Ratio, 52500 lb GVWR, Air Ride Cab, 60 in Mid Roof Sleeper Cab, Aluminum Wheels, 275/80R22.5 Front Tires, 295/75R22.5 Rear Tires, Air Assist Front Suspension, Air Ride Suspension, 249 in Wheelbase, Air Sliding 5th Wheel, Headache Rack, Dual Fuel Tanks