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

Cummins ISX 6 Cylinder Compressed Natural Gas (CNG) Engine, Air Conditioner, Cruise Control, Power Windows, Eaton Fuller FRO-15210C 10-Speed Manual Transmission, Differential Lock, 12000 lb Front Axle, 40000 lb Rears, 3.55:1 Axle Ratio, 52000 lb GVWR, Air Ride Cab, Aluminum Outer Wheels, 275/80R22.5 Front Tires, 275/80R22.5 Rear Tires, Air Ride Suspension, 187 in Wheelbase