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 ...

Low Traction Mode
If your vehicle has the Allison Transmission, or the Hydra-Matic 6-Speed Automatic Transmission, it has a Low Traction Mode that can assist in vehicle acceleration when road conditions are slippery, s ...

Finding a Station
To select the band, see “Audio Source” earlier in this section. Turn the MENU/SEL knob to find a radio station. To select a preset station, touch the FAV button and choose a preset station. Se ...