2009 CADILLAC CTS tire size

How to Check
Use a good quality pocket-type gage to check tire
pressure. You cannot tell if your tires are properly
inated simply by looking at them. Radial tires
may look properly inated even when they are
underinated. Check the tire’s ination pressure
when the tires are cold. Cold means your vehicle
has been sitting for at least three hours or driven
no more than 1 mile (1.6 km).
Remove the valve cap from the tire valve stem.
Press the tire gage rmly onto the valve to
get a pressure measurement. If the cold tire
ination pressure matches the recommended
pressure on the Tire and Loading Information
label, no further adjustment is necessary. If the
ination pressure is low, add air until you reach the
recommended amount.
If you overll the tire, release air by pushing on
the metal stem in the center of the tire valve.
Re-check the tire pressure with the tire gage.
Be sure to put the valve caps back on the valve
stems. They help prevent leaks by keeping out dirt
and moisture.
High-Speed Operation
{CAUTION:
Driving at high speeds, 100 mph (160 km/h) or
higher, puts an additional strain on tires. Sustained
high-speed driving causes excessive heat build up
and can cause sudden tire failure. You could have
a crash and you or others could be killed. Some
high-speed rated tires require ination pressure
adjustment for high speed operation. When speed
limits and road conditions are such that a vehicle
can be driven at high speeds, make sure the tires
are rated for high speed operation, in excellent
condition, and set to the correct cold tire ination
pressure for the vehicle load.
If your vehicle has 235/50ZR18, 255/40R19 or
285/35R19 size tires, they will require ination pressure
adjustment when driving your vehicle at speeds of
100 mph (160 km/h) or higher. Set the cold ination
pressure to the maximum ination pressure shown on
the tire sidewall, or 44 psi (300 kPa), whichever is lower.
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See the example following. When you end this
high-speed driving, return the tires to the cold tire
ination pressure shown on the Tire and Loading
Information label. SeeLoading the Vehicle on page 4-20
andInflation - Tire Pressure on page 5-69.
Example:
You will nd the maximum load and ination pressure
molded on the tire’s sidewall, in small letters, near
the rim ange. It will read something like this: Maximum
load 690 kg (1521 lbs) 300 kPa (44 psi) Max. Press.
For this example, you would set the ination pressure for
high-speed driving at 44 psi (300 kPa).
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.
Accordingly, when the low tire pressure telltale
illuminates, you should stop and check your tires as soon
as possible, and inate them to the proper pressure.
Driving on a signicantly under-inated tire causes the
tire to overheat and can lead to tire failure. Under-ination
also reduces fuel efficiency and tire tread life, and may
affect the vehicle’s handling and stopping ability.
Please note that the TPMS is not a substitute for proper
tire maintenance, and it is the driver’s responsibility to
maintain correct tire pressure, even if under-ination has
not reached the level to trigger illumination of the
TPMS low tire pressure telltale.
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Tire Pressure Monitor Operation
This vehicle may have a Tire Pressure Monitor System
(TPMS). 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, if the vehicle has one.
The TPMS sensors monitor the air pressure in the
vehicle’s tires and transmits the tire pressure readings
to a receiver located in the vehicle.
Using the Driver Information Center (DIC), the driver
can also check tire pressure levels using the DIC.
For additional information and details about the DIC
operation and displays seeDIC Operation and Displays
on page 3-51andDIC Warnings and Messages on
page 3-58.
When a low tire pressure
condition is detected, the
TPMS illuminates the
low tire pressure warning
light located on the
instrument panel cluster.
A DIC warning message to check the pressure in a
specic tire is also shown on the DIC display screen.
The low tire pressure warning light and the DIC warning
message come at each ignition cycle until the tires
are inated to the correct ination pressure.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.
The Tire and Loading Information label, attached to
your vehicle, shows the size of your vehicle’s original
equipment tires and the correct ination pressure for the
tires when they are cold. SeeLoading the Vehicle on
page 4-20, for an example of the Tire and Loading
Information label and its location on your vehicle.
Also seeInflation - Tire Pressure on page 5-69.
Your vehicle’s TPMS can warn you about a low tire
pressure condition but it does not replace normal
tire maintenance. SeeTire Inspection and Rotation on
page 5-76andTires on page 5-61.
Notice:Using non-approved tire sealants could
damage the Tire Pressure Monitor System (TPMS)
sensors. TPMS sensor damage caused by using
an incorrect tire sealant is not covered by the
vehicle warranty. Always use the GM approved tire
sealant available through your dealer/retailer.
Your vehicle, when new, included a factory-installed
Tire Inator Kit. This kit uses a GM approved liquid
tire sealant. Using non-approved tire sealants could
damage the TPMS sensors. SeeTire Sealant and
Compressor Kit on page 5-86for information regarding
the inator kit materials and instructions.
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Tire Inspection and Rotation
Inspect tires regularly for signs of wear or damage.
Also inspect the spare tire, if the vehicle has
one. For more information on tire inspection, see
When It Is Time for New Tires on page 5-77.
Tire rotation is not recommended if the vehicle has
255/40R19 size tires on the front wheels and
285/35R19 size tires on the rear wheels.
Different tire sizes should not be rotated front to
rear. Each tire and wheel should only be used
in its original front or rear position.
Tire rotation is recommended if the vehicle has
the same size tires on all four wheel positions.
These tires should be rotated every 5,000
to 8,000 miles (8 000 to 13 000 km). See
Scheduled Maintenance on page 6-4.
The purpose of a regular tire rotation is to achieve
a uniform wear for all tires on the vehicle. This
will ensure that your vehicle continues to perform
most like it did when the tires were new.Any time you notice unusual wear, rotate your
tires as soon as possible and check wheel
alignment. Also check for damaged tires or wheels.
SeeWhen It Is Time for New Tires on page 5-77
andWheel Replacement on page 5-82.
Use the rotation pattern shown here when rotating
tires of the same size installed on all four wheel
positions.
After the tires have been rotated, adjust the front
and rear ination pressures as shown on the Tire
and Loading Information label. SeeInflation - Tire
Pressure on page 5-69andLoading the Vehicle on
page 4-20.
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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.
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 5-63, for additional information.
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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 5-76.
Winter tires with the same speed rating as your
original equipment tires may not be available for H, V,
W, Y and ZR speed rated tires. If you choose snow tires
with a lower speed rating, never exceed the tire’s
maximum speed capability.
{CAUTION:
Mixing tires could cause you to lose control while
driving. If you mix tires of different sizes (other
than those originally installed on your vehicle),
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 (other
than those originally installed on your vehicle),
brands or types, may also cause damage to your
vehicle. Be sure to use the correct size, brand,
and type tires on all four wheels.
{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.
Vehicles that have a tire pressure monitoring system
could give an inaccurate low-pressure warning if
non-TPC Spec rated tires are installed on it. 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 5-71.
Your vehicle’s original equipment tires are listed on the
Tire and Loading Information label. SeeLoading the
Vehicle on page 4-20, for more information about
the Tire and Loading Information label and its location
on your vehicle.
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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 5-78andAccessories
and Modifications on page 5-3for additional information.
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.
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{CAUTION:
Incorrect wheel nuts or improperly tightened wheel
nuts can cause the wheel to become loose and
even come off. This could lead to a crash. Be sure
to use the correct wheel nuts. If you have to replace
them, be sure to get new GM original equipment
wheel nuts.
Notice:Improperly tightened wheel nuts can lead
to brake pulsation and rotor damage. To avoid
expensive brake repairs, evenly tighten the wheel
nuts in the proper sequence and to the proper
torque specication.
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. 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, re-adjust or remove the device if it is
contacting the vehicle, and do not spin the wheels.
If you do nd traction devices that will t, install
them on the rear tires.
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