See also:

California Fuel Requirements
If the vehicle is certified to meet California Emissions Standards, it is designed to operate on fuels that meet California specifications. See the underhood emission control label. If this fuel is n ...

Cellular and GPS Antennas
Avoid placing items over or near the antenna to prevent blocking cellular and GPS signal reception. Cellular reception is required for OnStar to send remote signals to the vehicle. ...

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 ...