See also:

Powertrain details
The GMC Sierra All Terrain HD concept is propelled by the new, production 6.6L Duramax turbo-diesel V-8 and Allison 1000 six-speed automatic transmission powertrain combination offered in the 2011 ...

Fuel
For diesel engine vehicles, see “Fuel for Diesel Engines” in the Duramax Diesel Supplement. For Vehicles with gasoline engines, please read this. ...

Lumbar Adjustment
Manual Lumbar If available, move the handle forward or rearward to increase or decrease lumbar support. Power Lumbar If available, press and hold the front or rear of control to increase or dec ...