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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Removing the Spare Tire and Tools
The equipment you will need is in the trunk.
Instructions for changing your tires are on the inside of
the tire cover located in your trunk.
To gain access to the instructions, spare tire and
jacking equipment, do the following:
1. Press the area at the
front of the handle
located on the cover so
that the back edge
raises.2. Grab the handle and
remove the cover.
3. Unscrew the wing nuts to remove the container that
holds the wrench and jack.
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4. Remove the wheel wrench, jack and compact spare
tire from the trunk. SeeCompact Spare Tire on
page 5-96for more information about the compact
spare tire.
The tools you will be using include the jack (A) and the
wheel wrench (B).Removing the Wheel Covers
For models having aluminum wheels with a center
wheel cover, use the at end of the wheel wrench to
gently pry the wheel covers off. Be careful not to scratch
the aluminum wheel edge and do not try to remove it
with your hands.
For models having wheel nuts exposed, use the wheel
wrench to remove the wheel nut covers.
Models with Center Wheel Cover
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