tires CADILLAC STS 2006 1.G Service Manual

Vehicles that have a tire pressure monitoring system
may 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.
Your vehicle’s original equipment tires are listed on
the Tire and Loading Information Label. This label
is attached to the vehicle’s center pillar (B-pillar). See
Loading Your Vehicle on page 4-32, 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 5-76.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 5-72andAccessories
and Modications on page 5-3for additional information.
5-74

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.
Treadwear
The treadwear grade is a comparative rating based on
the wear rate of the tire when tested under controlled
conditions on a specied government test course.
For example, a tire graded 150 would wear one and
a half (1.5) times as well on the government course as
a tire graded 100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart signicantly from the norm
due to variations in driving habits, service practices,
and differences in road characteristics and climate.
Traction – AA, A, B, C
The traction grades, from highest to lowest, are AA,
A, B, and C. Those grades represent the tire’s ability to
stop on wet pavement as measured under controlled
conditions on specied government test surfaces
of asphalt and concrete. A tire marked C may have
poor traction performance.
Warning:The traction grade assigned to this tire is
based on straight-ahead braking traction tests, and
does not include acceleration, cornering, hydroplaning,
or peak traction characteristics.
5-75

Temperature – A, B, C
The temperature grades are A (the highest), B, and C,
representing the tire’s resistance to the generation
of heat and its ability to dissipate heat when tested
under controlled conditions on a specied indoor
laboratory test wheel. Sustained high temperature
can cause the material of the tire to degenerate and
reduce tire life, and excessive temperature can lead
to sudden tire failure. The grade C corresponds to
a level of performance which all passenger car tires
must meet under the Federal Motor Vehicle Safety
Standard No. 109. Grades B and A represent higher
levels of performance on the laboratory test wheel than
the minimum required by law.
Warning:The temperature grade for this tire is
established for a tire that is properly inated and not
overloaded. Excessive speed, underination, or
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.
Wheel Alignment and Tire Balance
The tires and wheels on your vehicle were aligned
and balanced carefully at the factory to give you
the longest tire life and best overall performance.
Adjustments to wheel alignment and tire balancing will
not be necessary on a regular basis. However, if
you notice unusual tire wear or your vehicle pulling to
one side or the other, the alignment may need to
be checked. If you notice your vehicle vibrating when
driving on a smooth road, your tires and wheels
may need to be rebalanced. See your dealer for proper
diagnosis.
Wheel Replacement
Replace any wheel that is bent, cracked, or badly rusted
or corroded. If wheel nuts keep coming loose, the
wheel, wheel bolts, and wheel nuts should be replaced.
If the wheel leaks air, replace it (except some
aluminum wheels, which can sometimes be repaired).
See your dealer if any of these conditions exist.
Your dealer will know the kind of wheel you need.
Each new wheel should have the same load-carrying
capacity, diameter, width, offset and be mounted
the same way as the one it replaces.
5-76

If you need to replace any of your wheels, wheel bolts,
or wheel nuts, replace them only with new GM
original equipment parts. This way, you will be sure to
have the right wheel, wheel bolts, and wheel nuts
for your vehicle.
{CAUTION:
Using the wrong replacement wheels, wheel
bolts, or wheel nuts on your vehicle can be
dangerous. It could affect the braking and
handling of your vehicle, make your tires lose
air and make you lose control. You could have
a collision in which you or others could be
injured. Always use the correct wheel, wheel
bolts, and wheel nuts for replacement.
Notice:The wrong wheel can also cause problems
with bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper height,
vehicle ground clearance, and tire or tire chain
clearance to the body and chassis.
SeeChanging a Flat Tire (STS Only) on page 5-83for
more information.
Used Replacement Wheels
{CAUTION:
Putting a used wheel on your 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.
5-77

Tire Chains
{CAUTION:
If your vehicle has P255/45R17, P255/45R18,
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.
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 95S 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.
5-78

Notice:Lifting your vehicle improperly can damage
your vehicle and result in costly repairs not
covered by your warranty. To lift your vehicle
properly, follow the advice in this part.
To help prevent vehicle damage:
Be sure the jack you are using meets the weight
standards for your vehicle and is in good
working order.
Be sure to place a block or pad between the
jack and the vehicle.
Make sure the jack you are using only contacts
the jacking location lift points and is not leaning
on any other vehicle components such as the
rocker panels, the oor pan, or the stone guard
moldings.
Lift only in the areas shown in the following
pictures.
Lifting From the Front
The front lifting points can be accessed from either side
of your vehicle, behind the front tires.
1. Locate the front lifting points using the diagram
above. The front lifting location is about 15 inches
(37 cm) from the rear edge of the front wheel well.
2. Be sure to place a block or pad between the jack
and the vehicle.
3. Lift the vehicle with the jack, making sure the jack
is centered on the front lifting point.
5-80

Lifting From the Rear
The rear lifting points can be accessed from either side
of your vehicle, in front of the rear tires.
1. Locate the rear lifting points using the diagram
above. The rear lifting location is about 7 inches
(17 cm) from the front edge of the rear wheel well.
2. Be sure to place a block or pad between the jack
and the vehicle.
3. Lift the vehicle with the jack, making sure the jack
is centered on the rear lifting point.
SeeDoing Your Own Service Work on page 5-4.
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 5-56. 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.
5-81

If a tire goes at, and your vehicle has a spare tire, see
Changing a Flat Tire (STS Only) on page 5-83. 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.
Run-Flat Tires (STS-V)
If your vehicle has run-at tires, there is no spare tire
and no tire changing equipment. Run-at tires can
operate effectively with no air pressure for a limited
distance and speed. Your vehicle also has a Tire
Pressure Monitor (TPM) which will alert you if there
is a loss of tire pressure in any of the tires. These
tires perform so well without any air pressure that a
Tire Pressure Monitor (TPM) is used to alert you when
there is a low tire condition.
{CAUTION:
When the low tire warning light is displayed on
the instrument panel cluster, your vehicle’s
handling capabilities will be reduced during
severe maneuvers. If you drive too fast, you
could lose control of your vehicle. You or
others could be injured. Do not drive over
55 mph (90 km/h) when the low tire warning
light is displayed. Drive cautiously and check
your tire pressures as soon as you can.
5-82

SeeRun-Flat Tires (STS-V) on page 5-63andTire
Pressure Monitor System on page 5-66, for additional
information.
{CAUTION:
Special tools and procedures are required to
service a run-at tire. If these special tools
and procedures are not used you or others
could be injured and your vehicle could be
damaged. Always be sure the proper tools
and procedures, as described in the service
manual, are used.
To order a service manual seeService Publications
Ordering Information on page 7-14.
Changing a Flat Tire (STS Only)
If you have an STS-V model, there is no spare tire and
no tire changing equipment. Your vehicle is equipped
with run-at tires. SeeRun-Flat Tires (STS-V) on
page 5-63for more information. If you have an STS
model, follow the directions for changing a at tire in
this section.
If a tire goes at, avoid further tire and wheel damage
by driving slowly to a level place. Turn on your vehicle’s
hazard warning ashers. SeeHazard Warning Flashers
on page 3-6for more information.
5-83

Compact Spare Tire (STS Only)
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), so you can nish
your trip and have the full-size tire repaired or replaced
where you want. You must calibrate the tire ination
monitor system after installing or removing the compact
spare. SeeTire Pressure Monitor System on page 5-66.
The system may not work correctly when the compact
spare is installed on the vehicle. Of course, it’s best to
replace the spare with a full-size tire as soon as you can.
The spare will last longer and be in good shape in case
you need it again.
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.
Appearance Care
Cleaning the Inside of Your Vehicle
Your vehicle’s interior will continue to look its best if
it is cleaned often. Although not always visible, dust
and dirt can accumulate on your upholstery. Dirt
can damage carpet, fabric, leather, and plastic surfaces.
Regular vacuuming is recommended to remove
particles from your upholstery. It is important to keep
your upholstery from becoming and remaining heavily
soiled. Soils should be removed as quickly as possible.
Your vehicle’s interior may experience extremes of
heat that could cause stains to set rapidly.
Lighter colored interiors may require more frequent
cleaning. Use care because newspapers and garments
that transfer color to your home furnishings may also
transfer color to your vehicle’s interior.
5-94