2008 CHEVROLET IMPALA tire size

When It Is Time for New Tires
Various factors, such as maintenance, temperatures,
driving speeds, vehicle loading, and road conditions
inuence when you need new tires.
One way to tell when it is
time for new tires is to
check the treadwear
indicators, which will
appear when your tires
have only 1/16 inch
(1.6 mm) or less of tread
remaining.You need new tires if any of the following statements
are true:You can see the indicators at three or more places
around the tire.
You can see cord or fabric showing through the
tire’s rubber.
The tread or sidewall is cracked, cut, or snagged
deep enough to show cord or fabric.
The tire has a bump, bulge, or split.
The tire has a puncture, cut, or other damage that
cannot be repaired well because of the size or
location of the damage.
The rubber in tires degrades over time, even if they are
not being used. This is also true for the spare tire, if
your vehicle has one. Multiple conditions affect how fast
this aging takes place, including temperatures, loading
conditions, and ination pressure maintenance. With
proper care and maintenance tires will typically wear out
before they degrade due to age. If you are unsure
about the need to replace your tires as they get older,
consult the tire manufacturer for more information.
5-70

Buying New Tires
GM has developed and matched specic tires for your
vehicle. The original equipment tires installed on
your vehicle, when it was new, were designed to meet
General Motors Tire Performance Criteria Specication
(TPC Spec) system rating. If you need replacement
tires, GM strongly recommends that you get tires with
the same TPC Spec rating. This way, your vehicle
will continue to have tires that are designed to give the
same performance and vehicle safety, during normal
use, as the original tires.
GM’s exclusive TPC Spec system considers over a
dozen critical specications that impact the overall
performance of your vehicle, including brake system
performance, ride and handling, traction control, and tire
pressure monitoring performance. GM’s TPC Spec
number is molded onto the tire’s sidewall near the tire
size. If the tires have an all-season tread design,
the TPC Spec number will be followed by an MS for
mud and snow. SeeTire Sidewall Labeling on page 5-55
for additional information.GM recommends replacing tires in sets of four. This is
because uniform tread depth on all tires will help
keep your vehicle performing most like it did when the
tires were new. Replacing less than a full set of tires can
affect the braking and handling performance of your
vehicle. SeeTire Inspection and Rotation on page 5-68
for information on proper tire rotation.
{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different sizes,
brands, or types (radial and bias-belted tires),
the vehicle may not handle properly, and you
could have a crash. Using tires of different
sizes, brands, or types may also cause damage
to your vehicle. Be sure to use the correct size,
brand, and type of tires on all wheels. It is all
right to drive with your compact spare
temporarily, as it was developed for use on your
vehicle. SeeCompact Spare Tire on page 5-89.
5-71

{CAUTION:
If you use bias-ply tires on your vehicle,
the wheel rim anges could develop
cracks after many miles of driving. A tire
and/or wheel could fail suddenly, causing
a crash. Use only radial-ply tires with the
wheels on your vehicle.
If you must replace your vehicle’s tires with those that
do not have a TPC Spec number, make sure they
are the same size, load range, speed rating, and
construction type (radial and bias-belted tires) as your
vehicle’s original tires.
Vehicles that have a tire pressure monitoring system
could give an inaccurate low-pressure warning if
non-TPC Spec rated tires are installed on your vehicle.
Non-TPC Spec rated tires may give a low-pressure
warning that is higher or lower than the proper warning
level you would get with TPC Spec rated tires.
SeeTire Pressure Monitor System on page 5-63.
Your vehicle’s original equipment tires are listed on the
Tire and Loading Information Label. SeeLoading
Your Vehicle on page 4-21, for more information about
the Tire and Loading Information Label and its
location on your vehicle.
Different Size Tires and Wheels
If you add wheels or tires that are a different size than
your original equipment wheels and tires, this may
affect the way your vehicle performs, including its
braking, ride and handling characteristics, stability, and
resistance to rollover. Additionally, if your vehicle
has electronic systems such as, anti-lock brakes,
traction control, and electronic stability control, the
performance of these systems can be affected.
{CAUTION:
If you add different sized wheels, your vehicle
may not provide an acceptable level of
performance and safety if tires not
recommended for those wheels are selected.
You may increase the chance that you will
crash and suffer serious injury. Only use GM
specic wheel and tire systems developed for
your vehicle, and have them properly installed
by a GM certied technician.
SeeBuying New Tires on page 5-71andAccessories
and Modifications on page 5-3for additional information.
5-72

Tire Chains
{CAUTION:
If your vehicle has P225/55R17 or P235/50R18
size tires, 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, 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.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.
5-76

Storing a Flat or Spare Tire and
Tools (Base Model)
{CAUTION:
Storing a jack, a tire, or other equipment in the
passenger compartment of the vehicle could
cause injury. In a sudden stop or collision,
loose equipment could strike someone. Store
all these in the proper place.
After the compact spare tire has been installed on the
vehicle, store the at tire in the trunk.
When storing a full-size tire, use the extension with
the extension protector, located in the foam holder,
to help avoid wheel surface damage.To store a full-size tire:
1. Install the tools in their original location in the
trunk area and secure.
2. Place the tire valve stem facing down and
the protector/guide placed through a wheel
bolt hole.
3. Remove the protector and attach the retainer
securely
4. Store the cover as far forward as possible.
When storing a compact spare tire in the trunk, put the
protector back in the foam holder.
The compact spare is for temporary use only. Replace
the compact spare tire with a full-size tire as soon
as you can. SeeCompact Spare Tire on page 5-89.
Use this as a guide for storing the compact spare tire
and tools.
5-87

A. Cover
B. Retainer
C. Compact Spare Tire
D. Wing Nut
E. Jack
F. Wheel Wrench
G. Extension Protector
H. Foam Holder
I. Bolt ScrewA. Retainer
B. Full-Size Flat Tire
C. Protective Guide
D. Extension Bolt Screw
E. Wing Nut
F. Jack
G. Wheel Wrench
H. Foam Holder
I. Bolt Screw
Compact Spare Tire
Full-Size Flat Tire
5-88

Compact Spare Tire
Although the compact spare tire was fully inated
when the vehicle was new, it can lose air after a time.
Check the ination pressure regularly. It should be
60 psi (420 kPa).
After installing the compact spare on the vehicle, you
should stop as soon as possible and make sure the spare
tire is correctly inated. The compact spare is made to
perform well at speeds up to 65 mph (105 km/h) for
distances up to 3,000 miles (5 000 km), so you can nish
your trip and have the full-size tire repaired or replaced
where you want. You must calibrate the tire ination
monitor system after installing or removing the compact
spare. SeeTire Pressure Monitor System on page 5-63.
The system may not work correctly when the compact
spare is installed on the vehicle. Of course, it’s best to
replace the spare with a full-size tire as soon as you can.
The spare will last longer and be in good shape in case
you need it again.Notice:When the compact spare is installed,
do not take your vehicle through an automatic
car wash with guide rails. The compact spare can
get caught on the rails. That can damage the tire and
wheel, and maybe other parts of your vehicle.
Do not use the compact spare on other vehicles.
And do not mix the compact spare tire or wheel with
other wheels or tires. They will not t. Keep the
spare tire and its wheel together.
Notice:Tire chains will not t your compact spare.
Using them can damage your vehicle and can
damage the chains too. Do not use tire chains on
your compact spare.
5-89

Steering Wheel Controls, Audio.........................3-86
Steering Wheel, Tilt Wheel................................. 3-6
Storage Areas
Center Console Storage Area........................2-48
Convenience Net.........................................2-49
Cupholder(s)...............................................2-48
Glove Box..................................................2-48
Rear Seat Armrest.......................................2-48
Rear Storage Area.......................................2-48
Sunglasses Storage Compartment..................2-48
Stuck in Sand, Mud, Ice, or Snow.....................4-20
Sun Visors.....................................................2-17
Sunroof.........................................................2-49
T
Tachometer....................................................3-29
Taillamps
Turn Signal, Sidemarker, Stoplamps, and
Back-Up Lamps.......................................5-50
TCS Warning Light..........................................3-36
Theft-Deterrent, Radio.....................................3-85
Theft-Deterrent Systems...................................2-18
Content Theft-Deterrent................................2-18
PASS-Key
®III+...........................................2-19
PASS-Key®III+ Operation.............................2-20Tilt Wheel........................................................ 3-6
Time, Setting..................................................3-67
Tire
Pressure Light.............................................3-38
Tires.............................................................5-54
Aluminum Wheels, Cleaning..........................5-95
Buying New Tires........................................5-71
Chains.......................................................5-76
Changing a Flat Tire....................................5-78
Cleaning....................................................5-96
Compact Spare Tire.....................................5-89
Different Size..............................................5-72
If a Tire Goes Flat.......................................5-77
Ination - Tire Pressure................................5-61
Inspection and Rotation................................5-68
Installing the Spare Tire................................5-81
Pressure Monitor Operation...........................5-64
Pressure Monitor System..............................5-63
Removing the Flat Tire.................................5-81
Removing the Spare Tire and Tools...............5-79
Storing a Flat or Spare Tire and Tools............5-87
Tire Sidewall Labeling..................................5-55
Tire Terminology and Denitions....................5-58
Uniform Tire Quality Grading.........................5-73
Wheel Alignment and Tire Balance.................5-74
Wheel Replacement.....................................5-74
When It Is Time for New Tires......................5-70
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