
Black plate (56,1)Chevrolet Impala Owner Manual - 2011
10-56 Vehicle Care
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.All Passenger Car Tires Must
Conform to Federal Safety
Requirements In Addition To
These Grades.
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 (1½) 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, 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
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.

Black plate (57,1)Chevrolet Impala Owner Manual - 2011
Vehicle Care 10-57
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 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 tires and wheels on the vehicle
were aligned and balanced carefully
at the factory to give 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 there
is unusual tire wear or the vehicle
pulls to one side or the other, the
alignment should be checked. If the
vehicle vibrates when driving on a
smooth road, the tires and wheels
might need to be rebalanced. See
your dealer for proper diagnosis.
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.

Black plate (58,1)Chevrolet Impala Owner Manual - 2011
10-58 Vehicle Care
If you need to replace any of the
wheels, wheel bolts, wheel nuts,
or Tire Pressure Monitor System
(TPMS) sensors, replace them only
with new GM original equipment
parts. This way, you will be sure to
have the right wheel, wheel bolts,
wheel nuts, and TPMS sensors for
the vehicle.
{WARNING
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 If a Tire Goes Flat on
page 10‑59 for more information.
Used Replacement Wheels
{WARNING
Putting a used wheel on the
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
{WARNING
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 the 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 the
vehicle and tire size combination
and road conditions. Follow that
manufacturer's instructions.
(Continued)

Black plate (59,1)Chevrolet Impala Owner Manual - 2011
Vehicle Care 10-59
WARNING (Continued)
To help avoid damage to the
vehicle, drive slowly, readjust
or remove the device if it is
contacting the vehicle, and do not
spin the vehicle's wheels. If you
do find traction devices that will
fit, install them on the front tires.
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 flat tire
creates a drag that pulls the vehicle
toward that side. Take your foot off
the accelerator pedal and grip the
steering wheel firmly. Steer tomaintain lane position, and then
gently brake to a stop, well off the
road, if possible.
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.
{WARNING
Driving on a flat tire will cause
permanent damage to the tire.
Re-inflating a tire after it has been
driven on while severely
under-inflated or flat may cause a
blowout and a serious crash.
Never attempt to re-inflate a tire
that has been driven on while
severely under-inflated or flat.
(Continued)
WARNING (Continued)
Have your dealer or an authorized
tire service center repair or
replace the flat tire as soon
as possible.
{WARNING
Lifting a vehicle and getting under
it to do maintenance or repairs is
dangerous without the
appropriate safety equipment and
training. If a jack is provided with
the vehicle, it is designed only for
changing a flat tire. If it is used for
anything else, you or others could
be badly injured or killed if the
vehicle slips off the jack. If a jack
is provided with the vehicle, only
use it for changing a flat tire.

Black plate (60,1)Chevrolet Impala Owner Manual - 2011
10-60 Vehicle Care
If a tire goes flat, avoid further tire
and wheel damage by driving slowly
to a level place, well off the road,
if possible. Turn on the hazard
warning flashers. SeeHazard
Warning Flashers on page 6‑4.
{WARNING
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 firmly.
2. Put an automatic transmission shift lever in
P (Park), or shift a manual
transmission to 1 (First) or
R (Reverse).
(Continued)
WARNING (Continued)
3. Turn off the engine and donot restart while the vehicle
is raised.
4. Do not allow passengers to remain in the vehicle.
To be certain the vehicle will not
move, 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, at the opposite end of
the vehicle.
When the vehicle has a flat tire (B),
use the following example as a
guide to assist you in the placement
of wheel blocks (A).
A. Wheel Block
B. Flat Tire
The following information explains
how to repair or change a tire.

Black plate (63,1)Chevrolet Impala Owner Manual - 2011
Vehicle Care 10-63
3. For all wheel types, find thejacking location using the
diagram above and the
corresponding jacking notches
located on the bottom side of the
plastic molding. The notches in
the plastic molding are marked
with a triangle shape to help you
find them.
The front location is about
17.7 cm (7.0 in) from the rear
edge of the front wheel well. The
rear location is about 11.4 cm
(4.5 in) from the front edge of the
rear wheel well. 4. Put the compact spare tire
near you.
{WARNING
Getting under a vehicle when it is
jacked up is dangerous. If the
vehicle slips off the jack you could
be badly injured or killed. Never
get under a vehicle when it is
supported only by a jack.
{WARNING
Raising your vehicle with the jack
improperly positioned can
damage the vehicle and even
make the vehicle fall. To help
avoid personal injury and vehicle
damage, be sure to fit the jack lift
head into the proper location
before raising the vehicle.
{WARNING
Lifting a vehicle and getting under
it to do maintenance or repairs is
dangerous without the
appropriate safety equipment and
training. If a jack is provided with
the vehicle, it is designed only for
changing a flat tire. If it is used for
anything else, you or others could
be badly injured or killed if the
vehicle slips off the jack. If a jack
is provided with the vehicle, only
use it for changing a flat tire.

Black plate (64,1)Chevrolet Impala Owner Manual - 2011
10-64 Vehicle Care
5. Raise the vehicle by turning thejack handle clockwise. Raise the
vehicle far enough off the
ground to install the compact
spare tire.
6. Remove all wheel nuts and the flat tire.
{WARNING
Rust or dirt on a wheel, or on the
parts to which it is fastened, can
make wheel nuts become loose
after time. The wheel could come
off and cause an accident. When
changing a wheel, remove any
rust or dirt from places where the
wheel attaches to the vehicle. In
an emergency, use a cloth or a
paper towel to do this; but be sure
to use a scraper or wire brush
later, if needed, to get all the rust
or dirt off. See If a Tire Goes Flat
on page 10‑59.
7. Remove any rust or dirt from the wheel bolts, mounting surfaces,
and spare wheel.
8. Install the compact spare tire.
{WARNING
Never use oil or grease on bolts
or nuts because the nuts might
come loose. The vehicle's wheel
could fall off, causing a crash.

Black plate (65,1)Chevrolet Impala Owner Manual - 2011
Vehicle Care 10-65
9. Reinstall the wheel nuts with therounded end of the nuts toward
the wheel. Tighten each nut
clockwise by hand until the
wheel is held against the hub.10. Lower the vehicle by turning the jack handle
counterclockwise.
Lower the jack completely.
{WARNING
Wheel nuts that are improperly or
incorrectly tightened can cause
the wheels to become loose or
come off. The wheel nuts should
be tightened with a torque wrench
to the proper torque specification
after replacing. Follow the torque
specification supplied by the
aftermarket manufacturer when
using accessory locking wheel
nuts. See Capacities and
Specifications on page 12‑2 for
original equipment wheel nut
torque specifications.