Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent engine and fuel system deposits from forming,
allowing your emission control system to work properly.
You should not have to add anything to your fuel.
However, some gasolines contain only the minimum
amount of additive required to meet U.S. Environmental
Protection Agency regulations. General Motors
recommends that you buy gasolines that are advertised
to help keep fuel injectors and intake valves clean. If your
vehicle experiences problems due to dirty injectors or
valves, try a different brand of gasoline.
Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines may be available
in your area to contribute to clean air. General
Motors recommends that you use these gasolines,
particularly if they comply with the speci cations
described earlier.Notice:Your vehicle was not designed for fuel
that contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in your fuel
system and also damage the plastic and rubber
parts. That damage would not be covered under
your warranty.
Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. General Motors does
not recommend the use of such gasolines. Fuels
containing MMT can reduce the life of spark plugs and
the performance of the emission control system may
be affected. The malfunction indicator lamp may turn on.
If this occurs, return to your authorized GM dealer for
service.
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How to Check
Use a good quality pocket-type gage to check tire
pressure. You can’t tell if your tires are properly in ated
simply by looking at them. Radial tires may look properly
in ated even when they’re underin ated. Check the tire’s
in ation pressure when the tires are cold. Cold means
your vehicle has been sitting for at least three hours or
driven no more than 1 mile (1.6 km).
Remove the valve cap from the tire valve stem.
Press the tire gage rmly onto the valve to get a
pressure measurement. If the cold tire in ation pressure
matches the recommended pressure on the Tire and
Loading Information label, no further adjustment is
necessary. If the in ation pressure is low, add air
until you reach the recommended amount.
If you over ll the tire, release air by pushing on the
metal stem in the center of the tire valve. Recheck
the tire pressure with the tire gage.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt and
moisture.
Tire Inspection and Rotation
Tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km).
Any time you notice unusual wear, rotate your tires as
soon as possible and check wheel alignment. Also check
for damaged tires or wheels. SeeWhen It Is Time for
New Tires on page 5-59andWheel Replacement on
page 5-62for more information.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The rst rotation
is the most important. SeeScheduled Maintenance
on page 6-4, for scheduled rotation intervals.
When rotating your tires, always use the correct rotation
pattern shown here.
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