2009 CADILLAC STS tire size

Tire Pressure Monitor Operation
This vehicle may have a Tire Pressure Monitor System
(TPMS). The 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.
When a low tire pressure
condition is detected, the
TPMS illuminates the low
tire pressure warning light
located on the instrument
panel cluster.
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 by
the driver. For additional information and details about
the DIC operation and displays seeDIC Operation and
Displays on page 3-72andDIC Warnings and Messages
on page 3-79.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, attached to
your vehicle, shows the size of your vehicle’s original
equipment tires and the correct ination pressure for
your vehicle’s tires when they are cold. SeeLoading
the Vehicle on page 4-24for an example of the Tire and
Loading Information label and its location on your vehicle.
Also seeInflation - Tire Pressure on page 5-64.
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 5-71andTires on page 5-54.
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 5-87for information regarding the inator kit
materials and instructions.
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11. Set all four tires to the recommended air pressure
level as indicated on the tire and loading information
label.
12. Put the valve caps back on the valve stems.
Tire Inspection and Rotation
We recommend that you regularly inspect your
vehicle’s tires, including the spare tire, for signs
of wear or damage. SeeWhen It Is Time for
New Tires on page 5-73for more information.
Tire rotation is not recommended if your vehicle
has the following performance tire combinations:
P235/50R17 size tires on the front wheels
and P255/45R17 size tires on the rear wheels.
P235/50ZR18 size tires on the front wheels
and P255/45ZR18 size tires on the rear
wheels.
P255/45R18 size tires on the front wheels and
P275/40R19 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 the original front or rear position it is in.
Tire rotation is recommended if the vehicle is
equipped with P235/50R17 size tires on all four
wheel positions or 255/45ZR18 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).
SeeScheduled 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 the 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 5-73
andWheel Replacement on page 5-79.
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When rotating P235/50R17 size tires or
255/45ZR18 size tires, always use the correct
rotation pattern shown here.
If the vehicle has a compact spare tire, do not
include the compact spare tire in the tire rotation.
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 5-64andLoading the Vehicle on
page 4-24.Reset the Tire Pressure Monitor System. SeeTire
Pressure Monitor Operation on page 5-68.
Make certain that all wheel nuts are properly
tightened. See “Wheel Nut Torque” under
Capacities and Specifications on page 5-134.
{CAUTION:
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 you
change a wheel, remove any rust or dirt from
places where the wheel attaches to the
vehicle. In an emergency, you can 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. SeeChanging a Flat Tire on
page 5-104.
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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.
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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 5-56for
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.
The optional 18-inch performance tires,
size 255/45ZR18 99Y, used on some vehicles,
meets the General Motors Tire Performance
Criteria Specication (TPC Spec) rating but the
TPC Spec code has not been molded onto the tire’s
sidewall. If your vehicle has these tires, and you
need to replace them, you can still get these TPC
Spec rated tires by asking your GM dealer. Your
GM dealer can order these tires by part number.
This way, your vehicle will continue to give the
proper endurance, handling, traction, and ride
as the original tires.
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.
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{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 of tires on all
wheels. It is all right to drive with your vehicle’s
compact spare temporarily, it was developed for
use on your vehicle. SeeCompact Spare Tire on
page 5-114.
{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 5-66.
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Your vehicle’s original equipment tires are
listed on the Tire and Loading Information label.
SeeLoading the Vehicle on page 4-24, 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 5-74andAccessories
and Modifications on page 5-3for additional information.
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Tire Chains
{CAUTION:
If your VEHICLE has P255/45R17, P255/45ZR18,
P275/40R19, or 255/45ZR18 size tires, do not use
tire chains, as 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 your
vehicle and tire size combination and road
CAUTION: (Continued)
CAUTION: (Continued)
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 rear tires only.
Notice:If your vehicle has P235/50R17 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 rear
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.
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