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, 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
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.
While the tires available on General Motors passenger
cars and light trucks may vary with respect to these
grades, they must also conform to federal safety
requirements and additional General Motors Tire
Performance Criteria (TPC) standards.
Treadwear
The treadwear grade is a comparative rating based on
the wear rate of the tire when tested under controlled
conditions on a speci ed government test course.
For example, a tire graded 150 would wear one and
a half (1.5) times as well on the government course as
a tire graded 100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart signi cantly from the norm
due to variations in driving habits, service practices and
differences in road characteristics and climate.
Traction – AA, A, B, C
The traction grades, from highest to lowest, are AA, A,
B, and C. Those grades represent the tire’s ability
to stop on wet pavement as measured under controlled
conditions on speci ed government test surfaces of
asphalt and concrete. A tire marked C may have poor
traction performance. Warning: The traction grade
assigned to this tire is based on straight-ahead braking
traction tests, and does not include acceleration,
cornering, hydroplaning, or peak traction characteristics.
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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 speci ed 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 Vehicle 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 in ated and not
overloaded. Excessive speed, underin ation, or
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.
Wheel Alignment and Tire Balance
The wheels on your vehicle were aligned and balanced
carefully at the factory to give you the longest tire life
and best overall performance.
If you notice unusual tire wear or your vehicle pulling
one way or the other, the alignment may need to
be reset. If you notice your vehicle vibrating when driving
on a smooth road, your wheels may need to be
rebalanced.
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 if any of these conditions exist.
Your dealer 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.
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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.
{CAUTION:
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.
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 or tire chain
clearance to the body and chassis.
SeeChanging a Flat Tire on page 5-72for more
information.
Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You can’t know how it’s been used
or how far it’s been driven. It could fail
suddenly and cause a crash. If you have to
replace a wheel, use a new GM original
equipment wheel.
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Tire Chains
{CAUTION:
Don’t use tire chains. There’s 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
your 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 your vehicle and tire size combination and
road conditions. Follow that manufacturer’s
instructions. To help avoid damage to your
vehicle, drive slowly, readjust or remove the
device if it’s contacting your vehicle, and don’t
spin your wheels. If you do nd traction
devices that will t, install them on the front
tires for front-wheel-drive vehicles. If your
vehicle has all-wheel drive, install traction
devices on either the front tires or all four
tires, but never on the rear tires only.
Accessory In ator
Your vehicle may have an accessory in ator. With it, you
can in ate things like air mattresses and basketballs, and
you can also use it to bring your tires up to the proper
pressure.
The accessory in ator is located in the rear
compartment on the driver’s side. To remove the cover,
pull the tab on the cover and pull it off.
This is the symbol on the
accessory in ator switch.
There may be an accessory in ator kit stored in the
glove box. It includes a 20-foot (6 m) hose with an air
pressure gage and nozzle adapters.
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If a Tire Goes Flat
It’s unusual for a tire to “blowout” while you’re driving,
especially if you maintain your tires properly. If air goes
out of a tire, it’s much more likely to leak out slowly.
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 at tire will create a drag that
pulls the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel rmly.
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’d 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.{CAUTION:
Lifting a vehicle and getting under it to do
maintenance or repairs is dangerous without
the appropriate safety equipment and training.
The jack provided with your vehicle is
designed only for changing a at tire. If it is
used for anything else, you or others could be
badly injured or killed if the vehicle slips off
the jack. Use the jack provided with your
vehicle only for changing a at tire.
If a tire goes at, the next part shows how to use your
jacking equipment to change a at tire safely.
Changing a Flat Tire
If a tire goes at, avoid further tire and wheel damage
by driving slowly to a level place. Turn on your
hazard warning ashers.
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When you replace the compact spare with a full-size
tire, reinstall the bolt-on wheel covers or the center cap,
whichever your vehicle has. Tighten them hand tight
over the wheel nuts, using the folding wrench.
Compact Spare Tire
Although the compact spare tire was fully in ated when
your vehicle was new, it can lose air after a time.
Check the in ation pressure regularly. It should be
60 psi (420 kPa).
After installing the compact spare on your vehicle, you
should stop as soon as possible and make sure your
spare tire is correctly in ated. The compact spare is
made to perform well at speeds up to 65 mph (105 km/h)
for distances up to 3,000 miles (5 000 km), so you can
nish your trip and have your full-size tire repaired or
replaced where you want. Of course, it’s best to replace
your spare with a full-size tire as soon as you can. Your
spare will last longer and be in good shape in case you
need it again.
Notice:When the compact spare is installed, do
not take your vehicle through an automatic car wash
with guide rails. The compact spare can get
caught on the rails. That can damage the tire and
wheel, and maybe other parts of your vehicle.
Don’t use your compact spare on other vehicles.And don’t mix your compact spare tire or wheel with
other wheels or tires. They won’t t. Keep your spare tire
and its wheel together.
Notice:Tire chains will not t your compact spare.
Using them can damage your vehicle and can
damage the chains too. Do not use tire chains on
your compact spare.
All-Wheel Drive
After installing a compact spare tire on a vehicle with
all-wheel drive you will need to drive with light to
moderate acceleration, for 10 seconds, in a straight line.
This action will allow the vehicle to detect the compact
spare tire and disable the all-wheel drive system.
The AWD DISABLE message will come on in the
message center indicating that the all-wheel drive
system is off. You may detect a slight pull during this
time, but this is normal.
Notice:You may damage your vehicle’s all-wheel
drive system if your vehicle is driven for an
extended period with a compact spare tire installed
and the all-wheel drive system in operations. See
All-Wheel Drive (AWD) System on page 4-11for
more information.
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Aluminum or Chrome-Plated Wheels
The vehicle may be equipped with 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:If you use strong soaps, chemicals,
abrasive polishes, cleaners, brushes, or cleaners
that contain acid on aluminum or chrome-plated
wheels, you could damage the surface of the
wheel(s). The repairs would not be covered by your
warranty. Use only GM-approved cleaners on
aluminum or chrome-plated wheels.
The surface of these wheels is similar to the painted
surface of your vehicle. Do not use strong soaps,
chemicals, abrasive polishes, abrasive cleaners,
cleaners with acid, or abrasive cleaning brushes on
them because you could damage the surface. Do not
use chrome polish on aluminum wheels.
Notice:Using chrome polish on aluminum wheels
could damage the wheels. The repairs would not
be covered by your warranty. Use chrome polish on
chrome wheels only.Use chrome polish only on chrome-plated wheels, but
avoid any painted surface of the wheel, and buff off
immediately after application.
Notice:If you drive your vehicle through an
automatic car wash that has silicone carbide tire
cleaning brushes, you could damage the aluminum
or chrome-plated wheels. The repairs would not
be covered by your warranty. Never drive a vehicle
equipped with aluminum or chrome-plated wheels
through an automatic car wash that uses silicone
carbide tire cleaning brushes.
Do not take your vehicle through an automatic car wash
that has silicone carbide tire cleaning brushes. These
brushes can also damage the surface of these wheels.
Tires
To clean the tires, use a stiff brush with tire cleaner.
Notice:Using petroleum-based tire dressing
products on your vehicle may damage the paint
nish and/or tires. When applying a tire dressing,
always wipe off any overspray from all painted
surfaces on your vehicle.
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