2009 PONTIAC G8 tire size

Tire SizeRecommended Cold Tire Ination
Occupant and Cargo Weight: 573 lbs (260 kg) or Less Occupant and Cargo Weight:
Up to 917 lbs (416 kg)
(Vehicle Capacity Weight)
Front Tires Rear Tires Front Tires Rear Tires
P245/45R18 96V 35 psi (240 kPa) 35 psi (240 kPa) 39 psi (270 kPa) 44 psi (300 kPa) 245/45R18 96V 36 psi (250 kPa) 36 psi (250 kPa) 39 psi (270 kPa) 44 psi (300 kPa)
245/40R19 94W 36 psi (250 kPa) 36 psi (250 kPa) 39 psi (270 kPa) 44 psi (300 kPa)
When you end this high-speed
driving, return the tires to the cold tire
ination pressure shown on the Tire
and Loading Information label. See
Loading the Vehicle on page 8-30
and Inflation - Tire Pressure on
page 9-49 .
Tire Pressure Monitor
System
The Tire Pressure Monitor System
(TPMS) uses radio and sensor
technology to check tire pressure
levels. The TPMS sensors monitor
the air pressure in your vehicle’s tires
and transmit tire pressure readings to
a receiver located in the vehicle.
Each tire, including the spare
(if provided), should be checked
monthly when cold and inated to the
ination pressure recommended by
the vehicle manufacturer on the
vehicle placard or tire ination
pressure label. (If your vehicle has tires of a different size than the size
indicated on the vehicle placard or
tire ination pressure label, you
should determine the proper tire
ination pressure for those tires.)
As an added safety feature, your
vehicle has been equipped with a
tire pressure monitoring system
(TPMS) that illuminates a low tire
pressure telltale when one or
more of your tires is signicantly
under-inated.
9-52 Vehicle Service and Care

The TPMS operates on a radio
frequency and complies with
RSS-210 of Industry and Science
Canada. Operation is subject to the
following two conditions:
1. This device may not cause
interference.
2. This device must accept any
interference received, including
interference that may cause
undesired operation of the device.
Changes or modications to this
system by other than an authorized
service facility could void
authorization to use this equipment.Tire Pressure Monitor
Operation
The Tire Pressure Monitor System
(TPMS) is designed to warn the
driver when a low tire pressure
condition exists. TPMS sensors are
mounted onto each tire and
wheel assembly, excluding the
spare tire and wheel assembly. The
TPMS sensors monitor the air
pressure in the vehicle’s tires and
transmit the tire pressure readings to
a receiver located in the vehicle.
When a low tire pressure condition
is detected, the TPMS turns on the
7
low tire pressure warning light.
At the same time a message to
check the pressure in a specic tire
appears on the Driver Information
Center (DIC) display. The low tire
pressure warning light and the DIC
warning message come on at each
ignition cycle until the tires are
inated to the correct ination
pressure. Using the DIC, tire
pressure levels can be viewed bythe driver. For additional information
and details about the DIC operation
and displays seeDIC Operation and
Displays on page 4-22andDIC
Warnings and Messages on
page 4-26.
The low tire pressure warning light
may come on in cool weather
when the vehicle is rst started, and
then turn off as you start to drive.
This could be an early indicator that
the air pressure in the tire(s) are
getting low and need to be inated
to the proper pressure.
A Tire and Loading Information label
shows the size of the vehicle’s
original equipment tires and the
correct ination pressure for the
vehicle’s tires when they are cold.
SeeLoading the Vehicle on
page 8-30, for an example of the Tire
and Loading Information label and its
location on the vehicle. Also see
Inflation - Tire Pressure on
page 9-49.
9-54 Vehicle Service and Care

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 the 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 the 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 typically wear out beforethey degrade due to age. If you are
unsure about the need to replace
the tires as they get older, consult
the tire manufacturer for more
information.
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.
Vehicle Service and Care 9-59

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 9-42for 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 9-57for
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 9-83.{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.
9-60 Vehicle Service and Care

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 9-52.
Your vehicle’s original equipment
tires are listed on the Tire and
Loading Information Label. See
Loading the Vehicle on page 8-30,
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 9-59
andAccessories and Modifications
on page 9-3for additional
information.
Vehicle Service and Care 9-61

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.
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.
Vehicle Service and Care 9-65

Storing a Flat or Spare
Tire and Tools
{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.To store a at or spare tire and
tools, do the following:
A. Jack Handle
B. Nut Cap Tool
C. Wheel Wrench
D. Jack1. Replace the jack and tools as
shown.
2. Turn the retainer nut clockwise to
tighten.
3. Remove the wheel center cap by
pushing it from the back.
4. Place the at tire face up into the
spare tire hub.
5. Turn the retainer nut clockwise to
secure it into place.
6. Put the load oor back in place.
The compact spare tire is for
temporary use only. Replace the
compact spare with a full-size
tire as soon as possible.
9-82 Vehicle Service and Care

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, 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 at
your convenience. Of course, it is
best to replace the spare with a
full-size tire as soon as possible.
The spare tire will last longer and
be in good shape in case it is
needed again.Notice:When the compact spare
is installed, do not take the
vehicle through an automatic car
wash with guide rails. The
compact spare can get caught on
the rails which can damage the
tire, wheel and other parts of
the 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 the
compact spare. Using them can
damage the vehicle and can
damage the chains too. Do not use
tire chains on the compact spare.
Vehicle Service and Care 9-83