2008 CADILLAC STS wheel size

Your vehicle’s original equipment tires are listed on the
Tire and Loading Information label. SeeLoading
Your Vehicle on page 4-26, for more information about
the Tire and Loading Information label and its location
on your vehicle.
Vehicles that have performance tires P235/50R17 95V
(front axle) and P255/45R17 98V (rear axle) are mounted
on wheels with different rim widths. The front axle tires
are mounted on rims 7.5 inches (19.05 cm) wide and
the rear axle tires require wheels with a minimum rim
width of 8 inches (20.32 cm). The original equipment
wheels designed for P255/45R17 98V size tires are
etched with the words REAR ONLY. When replacing
P255/45R17 98V size tires have them mounted on
wheels with a minimum width of 8 inches (20.32 cm) and
marked REAR ONLY. SeeWheel Replacement on
page 5-80.
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, anti-lock 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 5-76andAccessories
and Modifications on page 5-3for additional information.
5-78

Tire Chains
{CAUTION:
If your vehicle has P255/45R17, P235/50ZR18,
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 your vehicle
and you or others may be injured in a crash.
CAUTION: (Continued)
CAUTION: (Continued)
Use another type of traction device only if its
manufacturer recommends it for use on your
vehicle and tire size combination and road
conditions. Follow that manufacturer’s
instructions. To help avoid damage to your
vehicle, drive slowly, readjust, or remove the
device if it is contacting your vehicle, and do
not spin your 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.
5-82

If a Tire Goes Flat
It is unusual for a tire to blowout while you are driving,
especially if you maintain your tires properly. See
Tires on page 5-57. If air goes out of a tire, It is much
more likely to leak out slowly. But if you should ever
have a blowout, here are a few tips about what to expect
and what to do:
If a front tire fails, the at tire will create a drag that
pulls the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel rmly.
Steer to maintain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you would
use in a skid. In any rear blowout, remove your foot from
the accelerator pedal. Get the vehicle under control
by steering the way you want the vehicle to go. It may
be very bumpy and noisy, but you can still steer. Gently
brake to a stop, well off the road if possible.
If a tire goes at, and your vehicle has a compact spare
tire, seeChanging a Flat Tire on page 5-96. This
information shows you how to use your vehicle’s tire
changing equipment and how to change a at tire safely.{CAUTION:
Lifting a vehicle and getting under it to do
maintenance or repairs is dangerous without
the appropriate safety equipment and training.
The jack provided with your vehicle is
designed only for changing a at tire. If it is
used for anything else, you or others could be
badly injured or killed if the vehicle slips off
the jack. Use the jack provided with your
vehicle only for changing a at tire.
If your vehicle has 255/45ZR18 size tires, there is no
spare tire, jack, or tire changing equipment. A tire inator
kit, included with your vehicle, may be used to seal
small punctures in the tread area of the tire. SeeTire
Sealant and Compressor Kit on page 5-87.
5-86

Full-Size Tire and Tools
After you have put the compact spare tire on your
vehicle, you will need to do the following to store the at
tire in your trunk.
1. Open the trunk. SeeTrunk on page 2-16.
2. Store the jack and wheel wrench in the jack
container in the trunk.
When storing the jack, in the container, it must be
raised until the screw end is ush with the edge
of the jack.
3. Store the at tire as far forward in the trunk as
possible.
The compact spare is for temporary use only. Replace
the compact spare tire with a full-size tire as soon
as you can.
Compact Spare Tire and Tools
Use the following diagram as a guide for storing the
compact spare tire and tools in the trunk:A. Compact
Spare Tire
Cover
B. Plastic Wing
Nut
C. RetainerD. Jack Container
Package (With Wheel
Wrench and Jack)
E. Compact Spare Tire
F. Foam Support
G. Bolt
1. Open the trunk. SeeTrunk on page 2-16.
2. Make sure the foam support (F) is in place in the
trunk area.
5-105

3. Reinstall the compact spare tire (E) making sure to
line up the wheel center hole with the bolt (G) and
place on the compartment oor.
4. Insert the jack container (D) with wheel wrench and
jack into the center of the compact spare tire
making sure to line up the wheel nut hole with the
bolt (G) on the compartment oor.
5. Secure the tire and wheel with the retainer (C) and
wing nut (B).
6. Reinstall the compact spare tire cover (A).
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, you
should 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). The tire ination
monitor system must be calibrated after installing or
removing the compact spare. SeeTire Pressure Monitor
System on page 5-68. The system may not work correctly
when the compact spare is installed on the vehicle.It’s best to replace the spare with a full-size tire as soon
as soon as possible. The spare will last longer and be in
good shape if needed it again.
If your vehicle has All Wheel Drive (AWD) it could also
have an StabiliTrak
®3. SeeStabiliTrak®System on
page 4-8for more information. If the compact spare tire
is installed on a vehicle with the StabiliTrak
®3
System, the vehicle operates in the Stability Secure
Mode. The STABILITY SECURE MODE message
displays on the Driver Information Center (DIC). See
DIC Warnings and Messages on page 3-80for
more information.
Notice:When the compact spare is installed, do
not take your vehicle through an automatic car wash
with guide rails. The compact spare can get
caught on the rails. That can damage the tire and
wheel, and maybe other parts of your 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 your compact spare.
Using them can damage your vehicle and can
damage the chains too. Do not use tire chains on
your compact spare.
5-106

Engine Coolant Level Check
Check the engine coolant level and add DEX-COOL®
coolant mixture if necessary. SeeEngine Coolant
on page 5-25.
Intercooler Coolant Level Check
(4.4L Supercharged Engine)
Check the coolant level and add DEX-COOL®coolant
mixture if necessary. SeeEngine Coolant on page 5-25.
Windshield Washer Fluid Level Check
Check the windshield washer uid level in the
windshield washer uid reservoir and add the proper
uid if necessary. SeeWindshield Washer Fluid
on page 5-40.
At Least Once a Month
Tire Ination Check
Inspect your vehicle’s tires and make sure they are
inated to the correct pressures. Do not forget to check
the spare tire. SeeInflation - Tire Pressure on
page 5-66. Check to make sure the spare tire is stored
securely. SeeChanging a Flat Tire on page 5-96.
Tire Wear Inspection
Tire rotation is recommended if your vehicle has the
same size tires at all four wheel positions and may be
required for high mileage highway drivers prior to
the Engine Oil Life System service notication.
Check the tires for wear and, if necessary, rotate the
tires. SeeTire Inspection and Rotation on page 5-73.
6-10

Storage Areas
Center Console Storage Area........................2-58
Convenience Net.........................................2-58
Cupholder(s)...............................................2-58
Glove Box..................................................2-58
Stuck in Sand, Mud, Ice, or Snow.....................4-25
Sun Visors.....................................................2-22
Sunroof.........................................................2-58
T
Tachometer....................................................3-59
TCS Warning Light..........................................3-65
Telescopic Steering Column, Power Tilt Wheel...... 3-7
Theft-Deterrent, Radio....................................3-121
Theft-Deterrent System....................................2-22
Theft-Deterrent Systems...................................2-22
Immobilizer.................................................2-26
Immobilizer Operation...................................2-26
Time, Setting..................................................3-99
Tire
Pressure Light.............................................3-67
Tires.............................................................5-57
Aluminum or Chrome-Plated Wheels,
Cleaning...............................................5-112
Buying New Tires........................................5-76
Chains.......................................................5-82
Changing a Flat Tire....................................5-96Tires (cont.)
Cleaning...................................................5-113
Compact Spare Tire...................................5-106
Different Size..............................................5-78
High-Speed Operation..................................5-68
If a Tire Goes Flat.......................................5-86
Ination - Tire Pressure................................5-66
Inspection and Rotation................................5-73
Installing the Spare Tire................................5-99
Lifting Your Vehicle......................................5-83
Pressure Monitor Operation...........................5-70
Pressure Monitor System..............................5-68
Removing the Flat Tire.................................5-99
Removing the Spare Tire and Tools...............5-98
Run-Flat.....................................................5-65
Storing a Flat or Spare Tire and Tools..........5-104
Tire Sealant and Compressor Kit...................5-87
Tire Sidewall Labeling..................................5-59
Tire Terminology and Denitions....................5-62
Uniform Tire Quality Grading.........................5-79
Wheel Alignment and Tire Balance.................5-80
Wheel Replacement.....................................5-80
When It Is Time for New Tires......................5-75
Winter Tires................................................5-58
Towing
Recreational Vehicle.....................................4-31
Towing a Trailer..................................4-34, 4-40
Your Vehicle...............................................4-31
12

W
Warning Lights, Gages and Indicators................3-57
Warnings
DIC Warnings and Messages........................3-80
Hazard Warning Flashers............................... 3-6
Other Warning Devices.................................. 3-6
Safety and Symbols......................................... iii
Vehicle Damage.............................................. iv
Washer, Headlamps........................................3-16
Wheels
Alignment and Tire Balance..........................5-80
Different Size..............................................5-78
Replacement...............................................5-80
Where to Put the Restraint...............................1-36
Windows.......................................................2-19
Power........................................................2-20
Windshield
Rainsense™ II Wipers..................................3-15
Replacement...............................................5-55
Washer......................................................3-16Windshield (cont.)
Washer Fluid..............................................5-40
Wiper Blade Replacement.............................5-55
Wiper Blades, Cleaning..............................5-112
Wiper Fuses.............................................5-117
Wipers.......................................................3-14
Winter Driving................................................4-22
Winter Tires...................................................5-58
Wiper Activated Headlamps..............................3-37
X
XM Radio Messages.....................................3-116
XM™ Satellite Radio Antenna System..............3-124
Y
Your Vehicle and the Environment....................... 6-2
14