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.
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 P225/55R17 or P235/50R18
size tires, 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 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 wheels.
If you do nd traction devices that will t,
install them on the front tires.Notice:If your vehicle has a tire size other than
P225/55R17 or P235/50R18 size tires, use tire chains
only where legal and only when you must. Use
only SAE Class S-type chains that are the proper
size for your tires. Install them on the front tires and
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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Use the at end of the wheel wrench and pry along the
edge of the cover until it comes off. The edge of the
wheel cover could be sharp, so do not try to remove it
with your bare hands. Do not drop the cover or lay
it face down, as it could become scratched or damaged.
Once you have removed the wheel cover, use the
following procedure to remove the at tire and install the
spare tire.
1. Turn the wheel wrench
once on each wheel nut
to loosen them. Do not
remove them yet.
2. For all wheel types, nd the jacking location using the
diagram above and the corresponding hoisting
notches located on the bottom side of the plastic
molding. The notches in the plastic molding are
marked with a triangle shape to help you nd them.
The front location is about 7.0 inches (17.7 cm) from
the rear edge of the front wheel well. The rear
location is about 4.5 inches (11.4 cm) from the rear
edge of the wheel well.
3. Put the compact spare tire near you.
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