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Overview
The GMC Sierra All Terrain HD concept is an exploration of heavy-duty truck capability combined with greater off-road versatility. It is highlighted by a bold exterior design, enhanced all-terrain ...

When to Check
Check the tires once a month or more. Do not forget the spare tire, if the vehicle has one. SeeFull-Size Spare Tire on page 10‑91 for additional information. ...

Driving on Grades
Reduce speed and shift to a lower gear before starting down a long or steep downgrade. If the transmission is not shifted down, the brakes might have to be used so much that they would get hot and ...