2009 CADILLAC STS wheel size

Tire Inspection and Rotation...........................5-71
When It Is Time for New Tires.......................5-73
Buying New Tires.........................................5-74
Different Size Tires and Wheels......................5-76
Uniform Tire Quality Grading..........................5-77
Wheel Alignment and Tire Balance..................5-79
Wheel Replacement......................................5-79
Tire Chains..................................................5-81
Lifting the Vehicle (STS-V).............................5-82
If a Tire Goes Flat........................................5-84
Tire Sealant and Compressor Kit
(Without Selector Switch)............................5-87
Tire Sealant and Compressor Kit
(With Selector Switch)................................5-96
Tire Sealant and Compressor Kit Storage.......5-104
Changing a Flat Tire...................................5-104
Removing the Spare Tire and Tools..............5-106
Removing the Flat Tire and Installing
the Spare Tire.........................................5-107
Storing a Flat or Spare Tire and Tools...........5-112
Compact Spare Tire....................................5-114
Appearance Care..........................................5-115
Interior Cleaning.........................................5-115
Fabric/Carpet..............................................5-116
Leather......................................................5-117
Instrument Panel, Vinyl, and Other
Plastic Surfaces.......................................5-117Wood Panels..............................................5-117
Speaker Covers..........................................5-118
Care of Safety Belts....................................5-118
Weatherstrips.............................................5-118
Washing Your Vehicle..................................5-118
Cleaning Exterior Lamps/Lenses....................5-119
Finish Care................................................5-119
Windshield and Wiper Blades.......................5-120
Aluminum or Chrome-Plated Wheels
and Trim................................................5-120
Tires.........................................................5-121
Sheet Metal Damage...................................5-121
Finish Damage...........................................5-121
Underbody Maintenance...............................5-121
Chemical Paint Spotting...............................5-122
Vehicle Identication.....................................5-122
Vehicle Identication Number (VIN)................5-122
Service Parts Identication Label...................5-122
Electrical System..........................................5-123
Add-On Electrical Equipment.........................5-123
Headlamp Wiring........................................5-123
Windshield Wiper Fuses...............................5-123
Power Windows and Other Power Options......5-123
Fuses and Circuit Breakers..........................5-123
Underhood Fuse Block................................5-124
Rear Underseat Fuse Block..........................5-128
Capacities and Specications........................5-134
Section 5 Service and Appearance Care
5-2

Low-Prole Performance Tires
If your vehicle has 255/45ZR18, P255/45R18
or P275/40R19 size tires, they are classied as
low-prole performance tires. These tires are
designed for very responsive driving on wet or
dry pavement. You may also notice more road
noise with low-prole performance tires and that
they tend to wear faster. These performance tires
are not rated as all-season tires. Winter tires are
recommended for snow or ice covered roads.
Notice:If the vehicle has low-prole tires, they
are more susceptible to damage from road
hazards or curb impact than standard prole
tires. Tire and/or wheel assembly damage
can occur when coming into contact with
road hazards like, potholes, or sharp edged
objects, or when sliding into a curb. The
vehicle warranty does not cover this type of
damage. Keep tires set to the correct ination
pressure and, when possible avoid contact
with curbs, potholes, and other road hazards.
Winter Tires
If you expect to drive on snow or ice covered roads
often, you may want to get winter tires for your vehicle.
All season tires provide good overall performance on
most surfaces but they may not offer the traction
you would like or the same level of performance
as winter tires on snow or ice covered roads.
Winter tires, in general, are designed for increased
traction on snow and ice covered roads. With winter
tires, there may be decreased dry road traction,
increased road noise, and shorter tread life. After
switching to winter tires, be alert for changes in
vehicle handling and braking.
See your dealer/retailer for details regarding winter tire
availability and proper tire selection. Also, seeBuying
New Tires on page 5-74.
If you choose to use winter tires:
Use tires of the same brand and tread type on all
four wheel positions.
Use only radial ply tires of the same size, load
range, and speed rating as the original equipment
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 winter tires with
a lower speed rating, never exceed the tire’s maximum
speed capability.
5-55

(F) Tire Size:A combination of letters and
numbers dene a tire’s width, height, aspect
ratio, construction type, and service description.
The letter T as the rst character in the tire
size means the tire is for temporary use only.
(G) TPC Spec (Tire Performance Criteria
Specication)
:Original equipment tires designed
to GM’s specic tire performance criteria have
a TPC specication code molded onto the sidewall.
GM’s TPC specications meet or exceed all
federal safety guidelines.
Tire Size
The following illustration shows an example of a
typical passenger vehicle tire size.
(A) Passenger (P-Metric) Tire
:The United States
version of a metric tire sizing system. The letter P
as the rst character in the tire size means a
passenger vehicle tire engineered to standards
set by the U.S. Tire and Rim Association.(B) Tire Width
:The three-digit number indicates
the tire section width in millimeters from sidewall
to sidewall.
(C) Aspect Ratio
:A two-digit number that
indicates the tire height-to-width measurements.
For example, if the tire size aspect ratio is 60, as
shown in item C of the illustration, it would mean
that the tire’s sidewall is 60 percent as high as it
is wide.
(D) Construction Code
:A letter code is used
to indicate the type of ply construction in the tire.
The letter R means radial ply construction; the
letter D means diagonal or bias ply construction;
and the letter B means belted-bias ply construction.
(E) Rim Diameter
:Diameter of the wheel in
inches.
(F) Service Description
:These characters
represent the load range and speed rating of the
tire. The load index represents the load carry
capacity a tire is certied to carry. The load index
can range from 1 to 279. The speed rating is the
maximum speed a tire is certied to carry a load.
Speed ratings range from A to Z.
5-58

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.
5-68

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.
5-71

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.
5-72

{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.
5-75

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.
5-76