Different Size Tires and Wheels
If you add wheels or tires that are a different size than
your original equipment wheels and tires, this may
affect the way your vehicle performs, including its
braking, ride and handling characteristics, stability,
and resistance to rollover . Additionally, if your vehicle
has electronic systems such as, antilock brakes,
traction control, and electronic stability control, the
performance of these systems can be affected.
{WARNING:
If you add different sized wheels, your vehicle
may not provide an acceptable level of
performance and safety if tires not recommended
for those wheels are selected. You may increase
the chance that you will crash and suffer serious
injury. Only use GM specific wheel and tire
systems developed for your vehicle, and have
them properly installed by a GM certified
technician.
See Buying New Tires
on page 6‑77andAccessories
and Modificationson page 6‑3for additional
information.
Uniform Tire Quality Grading
Quality grades can be found where applicable
on the tire sidewall between tread shoulder and
maximum section width. For example:
Treadwear 200 Traction AA
Temperature A
The following information relates to the system
developed by the United States National
Highway Traffic Safety Administration (NHTSA),
which grades tires by treadwear, traction, and
temperature performance. This applies only to
vehicles sold in the United States. The grades
are molded on the sidewalls of most passenger
car tires. The Uniform Tire Quality Grading
(UTQG) system does not apply to deep tread,
winter-type snow tires, space-saver, or temporary
use spare tires, tires with nominal rim diameters
of 10 to 12 inches (25 to 30 cm), or to some
limited-production tires.
6-79
Temperature–A, B, C
The temperature grades are A (the highest), B,
and C, representing the tire's resistance to the
generation of heat and its ability to dissipate
heat when tested under controlled conditions
on a specified indoor laboratory test wheel.
Sustained high temperature can cause the
material of the tire to degenerate and reduce
tire life, and excessive temperature can lead to
sudden tire failure. The grade C corresponds to
a level of performance which all passenger car
tires must meet under the Federal Motor Safety
Standard No. 109. Grades B and A represent
higher levels of performance on the laboratory
test wheel than the minimum required by law.
Warning: The temperature grade for this tire is
established for a tire that is properly inflated and
not overloaded. Excessive speed, underinflation,
or excessive loading, either separately or in
combination, can cause heat buildup and possible
tire failure.
Wheel Alignment and Tire Balance
The tires and wheels on your vehicle were aligned and
balanced carefully at the factory to give you the longest
tire life and best overall performance. Adjustments
to wheel alignment and tire balancing will not be
necessary on a regular basis. However, if you notice
unusual tire wear or your vehicle pulling to one side
or the other, the alignment might need to be checked.
If you notice your vehicle vibrating when driving on
a smooth road, the tires and wheels might need to
be rebalanced. See your dealer/retailer for proper
diagnosis.
Wheel Replacement
Replace any wheel that is bent, cracked, or badly
rusted or corroded. If wheel nuts keep coming loose,
the wheel, wheel bolts, and wheel nuts should be
replaced. If the wheel leaks air, replace it (except some
aluminum wheels, which can sometimes be repaired).
See your dealer/retailer if any of these conditions exist.
Your dealer/retailer will know the kind of wheel
you need.
Each new wheel should have the same load-carrying
capacity, diameter, width, offset, and be mounted the
same way as the one it replaces.
6-81
If you need to replace any of your wheels, wheel bolts
or wheel nuts, replace them only with new GM original
equipment parts. This way, you will be sure to have
the right wheel, wheel bolts, and wheel nuts for your
vehicle.
{WARNING:
Using the wrong replacement wheels, wheel bolts,
or wheel nuts on your vehicle can be dangerous.
It could affect the braking and handling of your
vehicle, make your tires lose air and make you
lose control. You could have a collision in which
you or others could be injured. Always use the
correct wheel, wheel bolts, and wheel nuts for
replacement.
{WARNING:
Putting a used wheel on the vehicle is dangerous.
You cannot know how it has been used or how
far it has been driven. It could fail suddenly and
cause a crash. If you have to replace a wheel,
use a new GM original equipment wheel. Notice:
The wrong wheel can also cause problems
with bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper height,
vehicle ground clearance, and tire clearance to the
body and chassis.
{WARNING:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after a time. The wheel could
come off and cause a crash. When you
change a wheel, remove any rust or dirt from
places where the wheel attaches to the
vehicle. In an emergency, you can use a
cloth or a paper towel to do this; but be sure
to use a scraper or wire brush later, if you
need to, to get all the rust or dirt off.
6-82
Tightening Wheel Lug Nuts
{WARNING:
Never use oil or grease on studs or the threads of
the wheel nuts. If you do, the wheel nuts might
come loose and the wheel could fall off, causing
a crash.
{WARNING:
Incorrect wheel nuts or improperly tightened wheel
nuts can cause the wheel to become loose and
even come off. This could lead to a crash. Be sure
to use the correct wheel nuts. If you have to
replace them, be sure to get new GM original
equipment wheel nuts. Notice:
Improperly tightened wheel nuts can lead
to brake pulsation and rotor damage. To avoid
expensive brake repairs, evenly tighten the wheel
nuts in the proper sequence and to the proper
torque specification.
Tighten the wheel lug nuts
firmly in a crisscross
sequence as shown.
6-83
Tire Chains
{WARNING:
Do not use tire chains. There is not enough
clearance. Tire chains used on a vehicle without
the proper amount of clearance can cause
damage to the brakes, suspension, or other
vehicle parts. The area damaged by the tire
chains could cause you to lose control of the
vehicle and you or others may be injured in a
crash. Use another type of traction device only
if its manufacturer recommends it for use on
the vehicle and tire size combination and
road conditions. Follow that manufacturer's
instructions. To help avoid damage to the vehicle,
drive slowly, re‐adjust or remove the device if
it is contacting the vehicle, and do not spin the
wheels. If you do find traction devices that will fit,
install them on the rear tires.
Lifting the Vehicle
{WARNING:
Lifting a vehicle can cause an injury. The vehicle
can slip off the jack and roll over you or other
people. You and they could be badly injured.
Find a level place to lift your vehicle. To help
prevent the vehicle from moving: 1. Set the parking brake firmly.
2. Put an automatic transmission shift lever in P (Park), or shift a manual transmission to
1 (First) or R (Reverse).
3. Turn off the engine.
To be even more certain the vehicle won't move,
you can put blocks in front of and behind the
wheels.
6-84
If a Tire Goes Flat
It is unusual for a tire to blow out while you are driving,
especially if you maintain the tires properly. If air goes
out of a tire, it is much more likely to leak out slowly.
See Tires
on page 6‑62for additional information.
But if you should ever have a blowout, here are a few
tips about what to expect and what to do:
If a front tire fails, the flat tire creates a drag that pulls
the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel firmly.
Steer to maintain lane position, and then gently brake
to a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you would
use in a skid. In any rear blowout remove your foot from
the accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle to go. It may be
very bumpy and noisy, but you can still steer. Gently
brake to a stop, well off the road if possible.
The vehicle has no spare tire, no tire changing
equipment, and no place to store a tire. The vehicle, when new, had run-flat tires. This type of
tire can operate effectively with no air pressure, so you
will not need to stop on the side of the road to change
a flat tire. You can just keep on driving. The shorter
the distance you drive and the slower the speed, the
greater the chance that the run-flat tire will not have to
be replaced. Run-flat tires perform so well without any
air that a Tire Pressure Monitor System (TPMS) is used
to alert you if a tire has lost pressure. See
Run-Flat
Tires
on page 6‑69and Tire Pressure Monitor Systemon page 6‑72.
{WARNING:
Special tools and procedures are required to
service a run-flat tire. If these special tools and
procedures are not used you or others could
be injured and the vehicle could be damaged.
Always be sure the proper tools and procedures,
as described in the service manual, are used.
To order a service manual, see Service Publications
Ordering Information on page 8‑16.
6-89
Washing Your Vehicle
The best way to preserve your vehicle's finish is to keep
it clean by washing it often.
Notice: Certain cleaners contain chemicals that can
damage the emblems or nameplates on the vehicle.
Check the cleaning product label. If it states that it
should not be used on plastic parts, do not use it on
the vehicle or damage may occur and it would not
be covered by the warranty.
Do not wash the vehicle in direct sunlight. Use a car
washing soap. Do not use cleaning agents that are
petroleum based or that contain acid or abrasives, as
they can damage the paint, metal or plastic on your
vehicle. Approved cleaning products can be obtained
from your dealer/retailer. Follow all manufacturers'
directions regarding correct product usage, necessary
safety precautions and appropriate disposal of any
vehicle care product.
Rinse the vehicle well, before washing and after to
remove all cleaning agents completely. If they are
allowed to dry on the surface, they could stain. Dry the finish with a soft, clean chamois or an all-cotton
towel to avoid surface scratches and water spotting.
Notice:
If you drive the vehicle through an
automatic car wash that does not have enough
clearance for the wide rear tires and wheels, you
could damage the vehicle. Verify with the manager
of the car wash that the vehicle will fit before
entering the car wash or use a touchless car wash.
High pressure car washes may cause water to enter the
vehicle. Avoid using high pressure washes closer than
12 inches (30 cm) to the surface of the vehicle. Use of
power washers exceeding 1,200 psi (8 274 kPa) can
result in damage or removal of paint and decals.
Cleaning Exterior Lamps/Lenses
Use only lukewarm or cold water, a soft cloth and a
car washing soap to clean exterior lamps and lenses.
Follow instructions under Washing Your Vehicle
on
page 6‑94.
6-94
Convertible Top
The vehicle's convertible top should be cleaned often.
However, high pressure car washes may cause water to
enter your vehicle.
When you hand wash the top, do it in partial shade.
Use a mild soap, lukewarm water and a soft sponge.
A chamois or cloth may leave lint on the top, and a
brush can chafe the threads in the top fabric. Do not
use detergents, harsh cleaners, solvents or bleaching
agents.
Wet the entire vehicle and wash the top evenly to avoid
spots or rings. Let the soap remain on the fabric for a
few minutes. When the top is really dirty, use a mild
foam-type cleaner. Thoroughly rinse the entire vehicle,
then let the top dry in direct sunlight.
To protect the convertible top:
.After you wash the vehicle, make sure the top is
completely dry before you lower it.
.Do not get any cleaner on the vehicle's painted
finish; it could leave streaks.
.If you decide to go through an automatic car wash,
ask the manager if the equipment could damage
your top.
Aluminum or Chrome-Plated Wheels
and Trim
The vehicle may have either aluminum or
chrome-plated wheels.
Keep the wheels clean using a soft clean cloth with mild
soap and water. Rinse with clean water. After rinsing
thoroughly, dry with a soft clean towel. A wax may then
be applied.
Notice: Chrome wheels and other chrome trim
may be damaged if the vehicle is not washed
after driving on roads that have been sprayed
with magnesium, calcium or sodium chloride.
These chlorides are used on roads for conditions
such as ice and dust. Always wash the vehicle's
chrome with soap and water after exposure.
Notice: Using strong soaps, chemicals, abrasive
polishes, cleaners, brushes, or cleaners that contain
acid on aluminum or chrome-plated wheels, could
damage the surface of the wheel(s). The repairs
would not be covered by the vehicle warranty.
Use only approved cleaners on aluminum or
chrome-plated wheels.
The surface of these wheels is similar to the painted
surface of the vehicle. Do not use strong soaps,
chemicals, abrasive polishes, abrasive cleaners,
6-97