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 ...
EPB Release
To release the EPB, place the
ignition in the ON/RUN position,
apply and hold the brake pedal, and
push down momentarily on the EPB
switch. If you attempt to release the
EPB without the brak ...
Cold Temperature Operation
If in an area of extreme cold, where the temperature
falls below −20°F (−29°C), use either an SAE 5W-30
synthetic oil or an SAE 0W-30 engine oil. Both provide
easier cold starting ...
