Gasoline Octane
Use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, you may notice an audible knocking noise when you drive, commonly referred to as spark knock. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible.
If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, your engine needs service.
See also:
Diagnostics
OnStar Vehicle Diagnostics will perform a vehicle check every month. It will
check the engine, transmission, antilock brakes, and major vehicle systems. It also
checks the tire pressures, if the v ...
StabiliTrak® System
The vehicle may have a vehicle stability enhancement system called StabiliTrak. It is an advanced computer-controlled system that assists with directional control of the vehicle in difficult driving c ...
Vehicle Care
To help keep the vehicle looking like
new, vehicle care products are
available from your dealer. For
information on how to clean and
protect the vehicle’s interior and
exterior, see Interi ...