2007 CHEVROLET IMPALA 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 (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 specied 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 signicantly 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 specied 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
specied 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 inated
and not overloaded. Excessive speed,
underination, or excessive loading, either
separately or in combination, can cause heat
buildup and possible tire failure.
Wheel Alignment and Tire Balance
The tires and wheels on your vehicle were aligned
and balanced carefully at the factory to give you
the longest tire life and best overall performance.
Adjustments to wheel alignment and tire
balancing will not be necessary on a regular basis.
However, if you notice unusual tire wear or your
vehicle pulling to one side or the other, the
alignment may need to be checked. If you notice
your vehicle vibrating when driving on a smooth
road, your tires and wheels may need to be
rebalanced. See your dealer/retailer for proper
diagnosis.
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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/retailer if any of these conditions exist.
Your dealer/retailer 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.
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.{CAUTION:
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.
SeeChanging a Flat Tire on page 374for more
information.
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Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You cannot know how it has
been used or how far it has been driven.
It could fail suddenly and cause a crash.
If you have to replace a wheel, use a new
GM original equipment wheel.
Tire Chains
{CAUTION:
If your vehicle has P225/55R17 or
P235/50R18 size tires, do not use tire
chains, there is not enough clearance.
CAUTION: (Continued)
CAUTION: (Continued)
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.
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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.
If a Tire Goes Flat
It is unusual for a tire to blowout while you are
driving, especially if you maintain your vehicle’s
tires properly. If air goes out of a tire, it is 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 at tire will create a drag that
pulls the vehicle toward that side. Take your foot off
the accelerator pedal and grip the steering wheel
rmly. 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 would 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.
{CAUTION:
Lifting a vehicle and getting under it to do
maintenance or repairs is dangerous
without the appropriate safety equipment
and training. The jack provided with your
vehicle is designed only for changing a
at tire. If it is used for anything else, you
or others could be badly injured or killed
if the vehicle slips off the jack. Use the
jack provided with your vehicle only for
changing a at tire.
If a tire goes at, the next part shows how to use the
jacking equipment to change a at tire safely.
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Changing a Flat Tire
If a tire goes at, avoid further tire and wheel
damage by driving slowly to a level place. Turn on
your vehicle’s hazard warning ashers. SeeHazard
Warning Flashers on page 152for more information.
{CAUTION:
Changing a tire can be dangerous. The
vehicle can slip off the jack and roll over
or fall on you or other people. You and
they could be badly injured or even killed.
Find a level place to change your tire. To
help prevent the vehicle from moving:
1. Set the parking brake rmly.
2. Put the shift lever in PARK (P).
3. Turn off the engine and do not restart
while the vehicle is raised.
4. Do not allow passengers to remain in
the vehicle.
To be even more certain the vehicle will
not move, you should put blocks at the
CAUTION: (Continued)
CAUTION: (Continued)
front and rear of the tire farthest away
from the one being changed. That would
be the tire, on the other side, at the
opposite end of the vehicle.
When your vehicle has a at tire, use the following
example as a guide to assist you in the placement
of wheel blocks.
The following information will tell you next how to
use the jack and change a tire.
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Removing the Spare Tire and Tools
The equipment you will need is located in
the trunk.
1. Open the trunk. SeeTrunk on page 102for
more information.
2. Remove the convenience net if the vehicle
has one.
3. Lift the handle on the spare tire cover. The
handle may hook on the front edge of the
trunk’s weatherstrip to hold the cover out of
the way.4. Turn the wing nut counterclockwise and
remove it.
5. Remove the compact spare tire.
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6. Turn the nut holding the jack counterclockwise
and remove it. Then remove the jack and
wrench.The tools you will need to change a tire include
the jack (A), extension and protection guide (B),
and wheel wrench (C).
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