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:
Ending a Call
Press
to end a call. ...
When the Light Is On Steady
This indicates that one or more of the tires are significantly underinflated.
A Driver Information Center (DIC) tire pressure message may also display. See
Vehicle Messages for more informati ...
Your Responsibility
Increase the volume of the radio if the OnStar advisor
cannot be heard.
If the light next to the OnStar buttons is red, the system
may not be functioning properly. Press
and request
a vehicle ...