
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.
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Tire Chains
{CAUTION:
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, re-adjust 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
rear tires.
Lifting the Vehicle
{CAUTION:
Lifting a vehicle can cause an injury. The
vehicle can slip off the jack and roll over you
or other people. You and they could be badly
injured. Find a level place to lift your vehicle.
To help prevent the vehicle from moving:
1. Set the parking brake rmly.
2. Put an automatic transmission shift lever
in PARK (P), or shift a manual
transmission to FIRST (1) or
REVERSE (R).
3. Turn off the engine.
To be even more certain the vehicle won’t
move, you can put blocks in front of and
behind the wheels.
5-81

If a Tire Goes Flat
Your vehicle has no spare tire, no tire changing
equipment, and no place to store a tire.
It is unusual for a tire to blow out while you are driving,
especially if you maintain your tires properly. If air
goes out of a tire, it is much more likely to leak out
slowly. SeeTires on page 5-58for additional
information.
Your vehicle, when new, had run- at tires. This type of
tire can operate effectively with no air pressure, so you
will not need to stop on the side of the road to change a
at tire. You can just keep on driving. The shorter the
distance you drive and the slower the speed, the greater
the chance that the run- at tire will not have to be
replaced. Run- at tires perform so well without any air
that a Tire Pressure Monitor System (TPMS) is used to
alert you if a tire has lost pressure. SeeRun-Flat Tires on
page 5-64andTire Pressure Monitor System on
page 5-68.{CAUTION:
Special tools and procedures are required to
service a run- at tire. If these special tools and
procedures are not used you or others could
be injured and your vehicle could be damaged.
Always be sure the proper tools and
procedures, as described in the service
manual, are used.
Notice:Using liquid sealants can damage the tire
valves and tire pressure monitor sensors in your
vehicle’s run- at tires. This damage would not
be covered by warranty. Do not use liquid sealants
in your vehicle’s run- at tires.
To order a service manual, seeService Publications
Ordering Information on page 7-17.
5-86

Convertible Top
The vehicle’s convertible top should be cleaned often.
However, high pressure car washes may cause water to
enter your vehicle.
When you hand wash the top, do it in partial shade.
Use a mild soap, lukewarm water and a soft sponge.
A chamois or cloth may leave lint on the top, and
a brush can chafe the threads in the top fabric. Do not
use detergents, harsh cleaners, solvents or bleaching
agents.
Wet the entire vehicle and wash the top evenly to avoid
spots or rings. Let the soap remain on the fabric for
a few minutes. When the top is really dirty, use a mild
foam-type cleaner. Thoroughly rinse the entire
vehicle, then let the top dry in direct sunlight.
To protect the convertible top:
After you wash the vehicle, make sure the top is
completely dry before you lower it.
Do not get any cleaner on the vehicle’s painted
nish; it could leave streaks.
If you decide to go through an automatic car wash,
ask the manager if the equipment could damage
your top.
Aluminum or Chrome-Plated Wheels
and Trim
Your vehicle may have either aluminum or
chrome-plated wheels.
Keep the wheels clean using a soft clean cloth with mild
soap and water. Rinse with clean water. After rinsing
thoroughly, dry with a soft clean towel. A wax may then
be applied.
Notice:Chrome wheels and other chrome trim may
be damaged if you do not wash your vehicle after
driving on roads that have been sprayed with
magnesium, calcium or sodium chloride. These
chlorides are used on roads for conditions such as
ice and dust. Always wash your vehicle’s chrome
with soap and water after exposure.
Notice:If you use strong soaps, chemicals,
abrasive polishes, cleaners, brushes, or cleaners
that contain acid on aluminum or chrome-plated
wheels, you could damage the surface of the
wheel(s). The repairs would not be covered by your
warranty. Use only approved cleaners on aluminum
or chrome-plated wheels.
5-94