See also:

Recommended Fuel
Use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, an audible knocking noise, commonly referred to as spark knock, might be heard when dri ...

All Terrain chassis and suspension
Based on the chassis of the 2011 Sierra HD trucks, the All Terrain HD features a fully boxed steel frame with exceptional strength and torsional stiffness. It incorporates the production models' n ...

Roof
Sunroof The ignition must be in ON/RUN or ACC/ACCESSORY to operate the sunroof and power sunshade. See Retained Accessory Power (RAP) on page 9‑20. The vehicle may have a sunroof over the fro ...