2008 PONTIAC G8 Owners Manual

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 9-40for 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 9-54for
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 the vehicle. Be
sure to use the correct size,
brand, and type of tires on
all wheels. It is all right to
drive with the compact
spare temporarily, as it was
developed for use on the
vehicle. SeeCompact Spare
Tire on page 9-79.{CAUTION
If you use bias-ply tires on
the 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 the
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.
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2008 - Pontiac G8 Owner Manual

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 9-49.
Your vehicle’s original equipment
tires are listed on the Tire and
Loading Information Label. See
Loading the Vehicle on page 8-28,
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, antilock
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 9-56
andAccessories and Modifications
on page 9-3for additional
information.
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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 gradesare 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.
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2008 - Pontiac G8 Owner Manual

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.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,
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2008 - Pontiac G8 Owner Manual

the alignment might need to be
checked. If you notice your vehicle
vibrating when driving on a
smooth road, the tires and wheels
might need to be rebalanced.
See your dealer/retailer 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/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 the
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 the 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 (V6
Engine) on page 9-71for more
information.
Used Replacement Wheels
{CAUTION
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.
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2008 - Pontiac G8 Owner Manual

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 the vehicle and you or others
may be injured in a crash.
(Continued)
CAUTION (Continued)
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. 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 nd traction devices
that will t, install them on the
front tires.
Tire Changing
If a Tire Goes Flat
It is unusual for a tire to blowout
while you are driving, especially if
you maintain your tires properly. See
Tires on page 9-39. 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.
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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.
If a tire goes at, and your vehicle
has a compact spare tire, see
Changing a Flat Tire (V6 Engine) on
page 9-71. This information shows
you how to use the vehicle’s
tire changing equipment and how to
change a at tire safely.{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.
Tire Sealant and
Compressor Kit
If your vehicle has a factory installed
Tire Sealant and Compressor kit,
there is no spare tire, no tire
changing equipment and no place to
store a tire.If a tire goes at, avoid further tire
and wheel damage by driving slowly
to a level place and stopping.
1. Turn on the hazard warning
ashers. SeeHazard Warning
Flashers on page 4-4.
2. Park your vehicle. Set the
parking brake rmly and put the
shift lever in PARK (P). See
Shifting Into Park (Automatic
Transmission) on page 8-10.
3. Turn off the engine.
4. Inspect the at tire.
If the tire has been separated from
the wheel, has damaged sidewalls,
or has a puncture larger than a
14inch (6 mm), the tire is too
severely damaged for the tire
sealant and compressor kit to be
effective. SeeRoadside Assistance
Program on page 12-6.
If the tire has a puncture less than a
14inch (6 mm) in the tread area
of the tire, seeTire Sealant
and Compressor Kit (V8 Engine) on
page 9-64.
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2008 - Pontiac G8 Owner Manual

Tire Sealant and
Compressor Kit
(V8 Engine)
This vehicle has a tire sealant and
compressor kit in place of a jack or
spare tire. It is located in a foam
container in the trunk. The tire
sealant and compressor kit can be
used to repair a at tire by sealing
small punctures in the tread of the
tire. It can also be used to inate an
underinated tire. The vehicle must
be driven for ve miles (8 kilometers)
after the tire is sealed and inated to
the recommended pressure to
ensure the sealant is distributed
evenly. For detailed instructions see
“Using the Tire Sealant and
Compressor Kit to Temporarily
Repair a Punctured Tire” later in this
section.The kit includes:
A. On/Off Switch
B. Air Compressor Accessory Plug
C. Air Compressor
D. Sealant Canister
E. Sealant/Air Hose
F. Air-only Hose
G. Pressure Gage
Tire Sealant
The sealant can temporarily seal a
small puncture up to 6 mm in
the tread area of the tire. The
sealant cannot seal sidewall
damage, large punctures, or a wheel
that has unseated from the wheel.
Read and follow the safe handling
instructions on the label adhered to
the sealant canister.
Check the tire sealant expiration
date on the sealant canister.
The sealant canister should be
replaced before its expiration date.
There is only enough sealant to
seal one tire. After usage, the
sealant canister and sealant/air hose
assembly must be replaced.
Replacement sealant canisters are
available from a dealer/retailer.
See “Removal and Installation of
Sealant Canister” later in this
section.
9-64 Vehicle Service and Care
2008 - Pontiac G8 Owner Manual