9-Speed Automatic
Transmission, 6-speed automatic, heavy-duty, electronically controlled with overdrive and tow/haul mode and internal transmission oil cooler
Transmission oil cooler, external
Brake/transmission shift interlock for automatic transmissions
Engine, Duramax 6.6L V8 Turbo Diesel (260 hp [193.9 kW] @ 3100 rpm, 525 lb-ft of torque [708.7 N-m] @ 1600 rpm) with B20 Bio-Diesel capability (see owner's manual for details) (Requires (KG3) 145 amp alternator, (GH0) 3.54 rear axle ratio, and (MYD) heavy-duty, 6-speed automatic transmission. With TG33406 models requires (C6Y) 9600 lbs. (4354) GVWR and (ZX5) 12-passenger seating. With TG33706 models requires (C4M) 9900 lbs. (4490 kg) GVWR and (ZX5) 12-passenger seating or (ZP3) 15-passenger seating.)