D12 12.1 L Diesel Engine, Engine Brake, Differential Lock, 12500 lb Front Axle, 38000 lb Rears, 3.58:1 Axle Ratio, 50350 lb GVWR, Air Ride Cab, 295/75R22.5, Air Ride Suspension, 190 in Wheelbase, Air Sliding 5th Wheel, Dual Fuel Tanks

6 Cylinder Diesel Engine, Air Conditioner, Cruise Control, Allison Automatic Transmission, 12000 lb Front Axle, 32000 lb Rears, 32000 lb GVWR, Air Ride Cab, 11R22.5 Front Tires, 11R22.5 Rear Tires, Air Ride Suspension, 159 in Wheelbase, Dual Fuel Tanks