Cummins ISB6.7 6 Cylinder 6.7 L Ultra Low Sulfur Diesel Engine, 2010 US EPA Label, Requires Diesel Exhaust Fluid, Allison Automatic Transmission, 295/75R22.5 Front Tires, 295/75R22.5 Rear Tires, 115 in Wheelbase, PTO, Hydraulic Lift 5th Wheel