2008 CADILLAC SRX wheel size

In addition, your vehicle has a passenger sensing
system for the right front passenger’s position, which
includes sensors that are part of the passenger’s
seat. The passenger sensing system may not
operate properly if the original seat trim is replaced
with non-GM covers, upholstery or trim, or with GM
covers, upholstery or trim designed for a different
vehicle. Any object, such as an aftermarket seat
heater or a comfort enhancing pad or device,
installed under or on top of the seat fabric, could also
interfere with the operation of the passenger sensing
system. This could either prevent proper deployment
of the passenger airbag(s) or prevent the passenger
sensing system from properly turning off the
passenger airbag(s). SeePassenger Sensing
System on page 1-65.
If you have any questions about this, you should
contact Customer Assistance before you modify
your vehicle. The phone numbers and addresses
for Customer Assistance are in Step Two of
the Customer Satisfaction Procedure in this manual.
SeeCustomer Satisfaction Procedure on page 7-2.
If your vehicle has rollover roof-rail airbags, see
Different Size Tires and Wheels on page 5-70
for additional important information.Q:Because I have a disability, I have to get my
vehicle modied. How can I nd out whether
this will affect my airbag system?
A:If you have questions, call Customer Assistance.
The phone numbers and addresses for Customer
Assistance are in Step Two of the Customer
Satisfaction Procedure in this manual. See
Customer Satisfaction Procedure on page 7-2.
In addition, your dealer/retailer and the service
manual have information about the location of the
airbag sensors, sensing and diagnostic module and
airbag wiring.
1-71

When It Is Time for New Tires.......................5-67
Buying New Tires.........................................5-68
Different Size Tires and Wheels......................5-70
Uniform Tire Quality Grading..........................5-70
Wheel Alignment and Tire Balance..................5-72
Wheel Replacement......................................5-72
Tire Chains..................................................5-74
If a Tire Goes Flat........................................5-75
Changing a Flat Tire.....................................5-76
Removing the Spare Tire and Tools................5-77
Removing the Flat Tire and Installing
the Spare Tire..........................................5-80
Secondary Latch System...............................5-84
Storing a Flat or Spare Tire and Tools............5-87
Compact Spare Tire......................................5-90
Appearance Care............................................5-91
Interior Cleaning...........................................5-91
Fabric/Carpet...............................................5-92
Leather.......................................................5-93
Instrument Panel, Vinyl, and
Other Plastic Surfaces................................5-93
Wood Panels...............................................5-93
Speaker Covers............................................5-93
Care of Safety Belts......................................5-94
Weatherstrips...............................................5-94
Washing Your Vehicle...................................5-94Cleaning Exterior Lamps/Lenses.....................5-94
Finish Care..................................................5-95
Windshield and Wiper Blades.........................5-95
Aluminun or Chrome-Plated Wheels and Trim.....5-96
Tires...........................................................5-96
Sheet Metal Damage.....................................5-97
Finish Damage.............................................5-97
Underbody Maintenance................................5-97
Chemical Paint Spotting.................................5-97
Vehicle Care/Appearance Materials..................5-98
Vehicle Identication......................................5-99
Vehicle Identication Number (VIN).................5-99
Service Parts Identication Label.....................5-99
Electrical System..........................................5-100
Add-On Electrical Equipment.........................5-100
Windshield Wiper Fuses...............................5-100
Power Windows and Other
Power Options........................................5-100
Fuses and Circuit Breakers..........................5-101
Underhood Fuse Block................................5-101
Rear Underseat Fuse Block (Left Side)..........5-105
Rear Underseat Fuse Block (Right Side)........5-108
Capacities and Specications........................5-111
Section 5 Service and Appearance Care
5-2

Low-Prole Performance Tire
If your vehicle has P255/50R20 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.
Notice:If your 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. Your
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 5-68.
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.
5-52

(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.
5-55

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 5-67for more information.
Tire rotation is not recommended if your vehicle has
the following tire combinations:
P235/65R17 size tires on the front wheels and
P255/60R17 size tires on the rear wheels.
P235/60R18 size tires on the front wheels and
P255/55R18 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 your vehicle is
equipped with P255/50R20 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 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 5-67andWheel
Replacement on page 5-72.When rotating P255/50R20 size tires, always use
the correct rotation pattern shown here.
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 5-59andLoading Your Vehicle
on page 4-33.
Reset the Tire Pressure Monitor System. See
Tire Pressure Monitor Operation on page 5-62.
Make certain that all wheel nuts are properly
tightened. See “Wheel Nut Torque” under
Capacities and Specifications on page 5-111.
5-66

{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 5-76.
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 appear
when your tires have
only 1/16 inch (1.6 mm) or
less of tread remaining.
Some commercial
truck tires may not have
treadwear indicators.
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.
5-67

{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 5-90.
{CAUTION:
If you use bias-ply tires on your 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 your 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 5-61.
Your vehicle’s original equipment tires are listed on
the Tire and Loading Information label. SeeLoading
Your Vehicle on page 4-33, for more information about
the Tire and Loading Information label and its location
on your vehicle.
5-69

Different Size Tires and Wheels
If you add wheels or tires that are a different size than
your original equipment wheels and tires, this could
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 anti-lock brakes, rollover
airbags, 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 5-68andAccessories
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.
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.
5-70