2003 PONTIAC GRAND PRIX Owners Manual

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 specified 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 significantly from the norm
due to variations in driving habits, service practices and
differences in road characteristics and climate.
Traction - AA, A, 9, 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 specified 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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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 specified 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.
Warning: The temperature grade for this tire
is
established for a tire that is properly inflated and not
overloaded. Excessive speed, underinflation, or
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.
Wheel Alignment and Tire Balance
The wheels on your vehicle were aligned and balanced
carefully at the factory to give you the longest tire life
and best overa!! performance.
Scheduled wheel alignment and wheel balancing are
not needed. However,
if you notice unusual tire wear or
your vehicle pulling one way or the other, the alignment
may need to be reset.
If you notice your vehicle
vibrating when driving on a smooth road, your wheels
may need to be rebalanced.
Wheel Replacement
Replace any wheel that is bent, cracked or badly rusted
or corroded. If wheel nuts keep coming loose, the
wheel, wheel bolts and wheel nuts should be replaced.
If the wheel leaks air, replace
it (except some
aluminum wheels, which can sometimes be repaired).
See your dealer
if any of these conditions exist.
Your dealer will know the kind of wheel you need.
Each new wheel should have the same load-carrying
capacity, diameter, width, offset and be mounted
the same way as the one it replaces.
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If you need to replace any of your wheels, wheel bolts
or wheel nuts, replace them only with new
GM
original equipment parts. This way, you will be sure to
have the right wheel, wheel bolts and wheel nuts
for your vehicle.
Using the wrong replacement wheels, wheel
bolts or wheel nuts on your vehicle can be
dangerous.
It could affect the braking and
handling
of your vehicle, make your tires lose
air and make you lose control. You could have
a collision
in which you or others could be
injured. Always use the correct wheel, wheel
bolts and wheel
nuts for replacement.
Notice: The wrong wheel can also cause problems
with bearing life, brake cooling, speedometer or odometer calibration, headlamp aim, bumper height.
vehicle ground clearance and tire or tire chain clearance to the body and chassis.
See Changing a Flat
Tire on page 5-76 for more
information.
Used Replacement Wheels
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Puttin, -1 used wheel on your vehicle is
dangerous. You can’t know how it’s been used
or how far
it’s been driven. It could fail suddenly
and cause a crash.
If you have to replace a
wheel, use a new
GM original equipment wheel.
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Tire Chains
If your vehicle is an SE model with P225/60R16
size tires, don’t use tire chains, there’s 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
CAUTION: (Continued) instructions. To help avoid damage to your
vehicle, drive slowly, readjust or remove the
device if
it’s contacting your vehicle, and don’t
spin your wheels.
If you do find traction devices that will fit,
install them on the front tires.
Notice; If your vehicle is a GT model, a GTP model,
or if you have an
SE model without P225/60R16
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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If a Tire Goes Flat
It’s unusual for a tire to “blow out” while you’re driving,
especially
if you maintain your tires properly. If air
goes out of a tire, it’s much more likely
to leak out
slowly. But
if you should ever have a “blowout”, here are
a few tips about what to expect and what to do:
If a front tire fails, the flat tire will create a drag that
pulls the vehicle toward that side. Take your foot
off the
accelerator pedal and grip the steering wheel firmly.
Steer to maintain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you’d use
in a skid. In any rear blowout, remove your foot from the
accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle to go.
It may be
very bumpy and noisy, but you can still steer. Gently
brake to a stop
- well off the road if possible.
If a tire goes flat, the next part shows how to use your
jacking equipment to change a flat tire safely.
Changing a Flat Tire
If a tire goes flat, avoid further tire and wheel damage
by driving slowly to a level place. Turn
on your
hazard warning flashers.
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Chant_ g a tire can cause an injury. The v icle
can slip
off the jack and roll over you or other
people.
You and they could be badly injured.
Find a level place to change your tire. To help
prevent the vehicle from moving:
1. Set the parking brake firmly.
2. Put the shift lever in PARK (P).
3. Turn off the engine.
To be even more certain the vehicle won’t move, you can put blocks at the front and
rear of the tire farthest away from
the one
being changed. That would be the tire on
the other side of the vehicle, at the
opposite end.
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2. Remove the compact spare tire. See Compact
Spare Tire
on page 5-87 for more information
about the compact spare tire.
3. Turn the nut holding the jack counterclockwise and
remove it. Then remove the jack and wrench.
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4. The tools you’ll be using include the jack (A)
extension and protector/guide (B) and the wheel
wrench
(C).
Removing Wheel Covers and Wheel
Nut Caps
If there is a wheel cover,
loosen the plastic nut caps
with the wheel wrench.
They won’t come
off. Then,
using the flat end of the
wheel wrench,
pry
along the edge of the
cover until it comes
off.
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