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 LT285/75R16 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 has a tire size other than
LT285/75R16 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. Do not 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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4. Reinstall the wing nut retainer to fasten the jack
and tool bag in the storage compartment.
Make sure that the wing nut passes through the tool
bag and the jack before you tighten it.
5. Turn the wing nut retainer clockwise to secure.
6. Reinstall the compartment cover by inserting
the locator tabs in the holes in the swing-gate.
Push the latches down to secure.
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 5-60andLoading Your Vehicle on page 4-52
for information regarding proper tire in ation and loading
your vehicle. For instruction on how to remove, install
or store a spare tire, seeChanging a Flat Tire on
page 5-73andRemoving the Flat Tire and Installing the
Spare Tire on page 5-77.
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 that were originally installed on your
vehicle. This spare tires was developed for use on your
vehicle, so it’s all right to drive on it.
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.
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