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 driving.
If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. If heavy knocking is heard when using gasoline rated at 87 octane or higher, the engine needs service.
See also:
Tow/Haul Mode
Pressing this button at the end of the shift lever turns on and off the Tow/Haul Mode.
This indicator light on the instrument panel cluster comes on when the Tow/Haul Mode is on.
Tow/Haul is a f ...
Connections
OnStar Hands-Free Calling allows calls to be made and received from the vehicle.
The vehicle can also be controlled from a cell phone through the OnStar mobile app.
See www.onstar.com for coverage ...
Cooling System
If the vehicle has the Duramax® Diesel engine, see the Duramax® Diesel Supplement for more information.
The cooling system allows the engine to maintain the correct working temperature.
5.3 L En ...