Volvo D13 6 Cylinder Ultra Low Sulfur Diesel 425 hp Engine, Air Conditioner, Power Windows, Engine Brake, 12350 lb Front Axle, 22700 lb Rears, 35050 lb GVWR, Aluminum Wheels, 295/75R22.5 Front Tires, 295/75R22.5 Rear Tires, Air Ride Suspension, 159 in Wheelbase, Air Sliding 5th Wheel, Dual Fuel Tanks