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.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. It should
be noted that the temperature
grade for this tire is established
for a tire that is properly
in ated and not overloaded.
Service and Appearance Care 5-53
2. Unwrap the sealant/air hose (F)
and the power plug (H).
3. Place the kit on the ground.
Make sure the tire valve
stem is positioned close to the
ground so the hose will reach it.
4. Remove the valve stem cap from
the at tire by turning it
counterclockwise.
5. Attach the sealant/air hose (F)
onto the tire valve stem. Turn
it clockwise until it is tight.
6. Plug the power plug (H) into the
accessory power outlet in the
vehicle. Unplug all items from
other accessory power outlets.
SeeAccessory Power Outlet(s)
on page 3-17.
If the vehicle has an accessory
power outlet, do not use the
cigarette lighter.
If the vehicle only has a cigarette
lighter, use the cigarette lighter.
Do not pinch the power plug
cord in the door or window.7. Start the vehicle. The vehicle
must be running while using
the air compressor.
8. Turn the selector switch (A)
counterclockwise to the
Sealant + Air position.
9. Press the on/off (B) button to
turn the tire sealant and
compressor kit on.
The compressor will inject
sealant and air into the tire.
The pressure gage (C) will initially
show a high pressure while the
compressor pushes the sealant
into the tire. Once the sealant is
completely dispersed into the tire,
the pressure will quickly drop and
start to rise again as the tire
in ates with air only.10. In ate the tire to the
recommended in ation
pressure using the pressure
gage (C). The recommended
in ation pressure can be
found on the Tire and Loading
Information label. See
Inflation - Tire Pressure on
page 5-42.
The pressure gage (C) may
read higher than the actual tire
pressure while the compressor
is on. Turn the compressor
off to get an accurate pressure
reading. The compressor
may be turned on/off until the
correct pressure is reached.
5-60 Service and Appearance Care