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When It Is Time for New Tires
One way to tell when it is
time for new tires is to
check the treadwear
indicators, which will
appear when your tires
have only 1/16 inch
(1.6 mm) or less of
tread remaining.
Some commercial truck
tires may not have
treadwear indicators.
You need a new tire if any of the following statements
are true:
You can see the indicators at three or more places
around the tire.
You can see cord or fabric showing through the
tire’s rubber.
The tread or sidewall is cracked, cut or snagged
deep enough to show cord or fabric.
The tire has a bump, bulge or split.
The tire has a puncture, cut or other damage that
cannot be repaired well because of the size or
location of the damage.
Buying New Tires
To nd out what kind and size of tires you need, look at
the Certi cation/Tire label. SeeLoading Your Vehicle
on page 4-50, for more information about this
Certi cation/Tire label and where it can be found on
your vehicle.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Speci cations (TPC Spec)
number on each tire’s sidewall. When you get new tires,
GM recommends that you get tires with that same
TPC Spec number. That way your vehicle will continue
to have tires that are designed to give proper
endurance, handling, speed rating, load range, traction,
ride, and other things during normal service on your
vehicle. If your tires have an all-season tread design,
the TPC number will be followed by an “MS”
(for mud and snow).
Whenever you replace your tires with those not having
a TPC Spec number, make sure they are the same
size, load range, speed rating and construction
type (bias, bias-belted or radial) as your original tires.
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{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different sizes,
brands or types (radial and bias-belted tires),
the vehicle may not handle properly, and you
could have a crash. Using tires of different
sizes, brands or types may also cause damage
to your vehicle. Be sure to use the same size,
brand, and type tires on all wheels.
Your vehicle may be equipped with a different
size spare than the road tires (those originally
installed on your vehicle). When new, your
vehicle included a spare tire and wheel
assembly with a similar overall diameter as
your vehicle’s road tires and wheels, so it is all
right to drive on it. Because this spare was
developed for use on your vehicle, it will not
affect vehicle handling.
{CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rim anges could develop cracks after
many miles of driving. A tire and/or wheel
could fail suddenly, causing a crash.
Use only radial-ply tires with the wheels on
your vehicle.
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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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Tire Chains
{CAUTION:
If your vehicle has dual wheels or P265/75R16,
LT265/75R16, P265/70R17 or P275/55R20 size
tires, do not use tire chains. They can damage
your vehicle because 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
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 is contacting your vehicle, and do
not spin your vehicle’s wheels.
If you do nd traction devices that will t,
install them on the rear tires.Notice:If your vehicle does not have dual wheels
and is equipped with a tire size other than
P265/75R16, LT265/75R16, P265/70R17 or
P275/55R20, use tire chains only where legal and
only when you must. Use chains that are the proper
size for your tires. Install them on the tires of the
rear axle. Don’t use chains on the tires of the front
axle. Tighten them as tightly as possible with
the ends securely fastened. Drive slowly and follow
the chain manufacturer’s instructions. If you can
hear the chains contacting your vehicle, stop
and retighten them. If the contact continues, slow
down until it stops. Driving too fast or spinning the
wheels with chains on will damage your vehicle.
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Spare Tire
Your vehicle, when new, had a fully-in ated spare tire.
A spare tire may lose air over time, so check its
in ation pressure regularly. SeeIn ation - Tire Pressure
on page 5-80andLoading Your Vehicle on page 4-50
for information regarding proper tire in ation and loading
your vehicle. For instruction on how to remove, install
or store a spare tire, seeRemoving the Flat Tire
and Installing the Spare Tire on page 5-96andStoring
a Flat or Spare Tire and Tools on page 5-108.
After installing the spare tire on your vehicle, you should
stop as soon as possible and make sure the spare is
correctly in ated. Have the damaged or at road
tire repaired or replaced as soon as you can and
installed back onto your vehicle. This way, a spare tire
will be available in case you need it again.
Your vehicle may have a different size spare tire than
the road tires originally installed on your vehicle.
This spare tire was developed for use on your vehicle,
so it is all right to drive on it. If your vehicle has
four-wheel drive and the smaller spare is installed, keep
the vehicle in two-wheel drive as much as possible.
If your vehicle has a spare tire that does not match your
vehicle’s original road tires and wheels in size and
type, do not include the spare in the tire rotation.
Appearance Care
Cleaning products can be hazardous. Some are toxic.
Other cleaning products can burst into ames if a match
is struck near them or if they get on a hot part of the
vehicle. Some are dangerous if their fumes are inhaled
in an enclosed space. When anything from a container
is used to clean the vehicle, be sure to follow the
manufacturer’s warnings and instructions. Always open
the doors or windows of the vehicle when cleaning
the inside.
Never use these to clean the vehicle:
Benzene
Naphtha
Carbon Tetrachloride
Acetone
Paint Thinner
Turpentine
Lacquer Thinner
Nail Polish Remover
They can all be hazardous — some more than
others — and they can all damage the vehicle, too.
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