CADILLAC STS 2007 1.G Owners Manual

Tires
Your new vehicle comes with high-quality tires
made by a leading tire manufacturer. If you ever
have questions about your tire warranty and where
to obtain service, see your GM Warranty booklet for
details. For additional information refer to the tire
manufacturer’s booklet included with your vehicle.
{CAUTION:
Poorly maintained and improperly
used tires are dangerous.
Overloading your tires can cause
overheating as a result of too much
friction. You could have an air-out and
a serious accident. SeeLoading Your
Vehicle on page 349.
CAUTION: (Continued)
CAUTION: (Continued)

Underinated tires pose the same
danger as overloaded tires. The
resulting accident could cause serious
injury. Check all tires frequently to
maintain the recommended pressure.
Tire pressure should be checked when
your tires are cold. SeeInflation - Tire
Pressure on page 431.
Overinated tires are more likely to be
cut, punctured, or broken by a sudden
impact — such as when you hit a
pothole. Keep tires at the
recommended pressure.
Worn, old tires can cause accidents. If
your tread is badly worn, or if your tires
have been damaged, replace them.
SeeHigh-Speed Operation on page 432for
ination pressure adjustment for high
speed driving.
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Low-Prole Performance Tires
If your vehicle has 255/45ZR18, P255/45R18 or
P275/40R19 100Y 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 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 GM
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 overallperformance 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 for details regarding winter tire
availability and proper tire selection. Also,
seeBuying New Tires on page 441.
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.
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Tire Sidewall Labeling
Useful information about a tire is molded into its
sidewall. The examples below show a typical
passenger vehicle tire and a compact spare tire
sidewall.(A) Tire Size:The tire size is a combination of
letters and numbers used to dene a particular
tire’s width, height, aspect ratio, construction type,
and service description. See the “Tire Size”
illustration later in this section for more detail.
(B) 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.
(C) DOT (Department of Transportation):The
Department of Transportation (DOT) code
indicates that the tire is in compliance with the
U.S. Department of Transportation Motor Vehicle
Safety Standards.
(D) Tire Identication Number (TIN):The letters
and numbers following DOT (Department of
Transportation) code is the Tire Identication
Number (TIN). The TIN shows the manufacturer
and plant code, tire size, and date the tire
was manufactured. The TIN is molded onto both
sides of the tire, although only one side may have
the date of manufacture.
Passenger (P-Metric) Tire Example
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(E) Tire Ply Material:The type of cord and
number of plies in the sidewall and under the tread.
(F) Uniform Tire Quality Grading (UTQG):Tire
manufacturers are required to grade tires
based on three performance factors: treadwear,
traction, and temperature resistance. For more
information seeUniform Tire Quality Grading on
page 444.
(G) Maximum Cold Ination Load Limit:
Maximum load that can be carried and the
maximum pressure needed to support that load.
(A) Temporary Use Only:The compact spare
tire or temporary use tire has a tread life of
approximately 3,000 miles (5 000 km) and should
not be driven at speeds over 65 mph (105 km/h).
The compact spare tire is for emergency use when
a regular road tire has lost air and gone at. If
your vehicle has a compact spare tire, see
Compact Spare Tire on page 475andIf a Tire
Goes Flat on page 451.
Compact Spare Tire Example
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(B) Tire Ply Material:The type of cord and
number of plies in the sidewall and under the tread.
(C) Tire Identication Number (TIN):The letters
and numbers following the DOT (Department of
Transportation) code is the Tire Identication
Number (TIN). The TIN shows the manufacturer
and plant code, tire size, and date the tire
was manufactured. The TIN is molded onto both
sides of the tire, although only one side may have
the date of manufacture.
(D) Maximum Cold Ination Load
Limit:Maximum load that can be carried and the
maximum pressure needed to support that load.
(E) Tire Ination:The temporary use tire or
compact spare tire should be inated to 60 psi
(420 kPa). For more information on tire pressure
and ination seeInation - Tire Pressure on
page 431.
(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.
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(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.Tire Terminology and Denitions
Air Pressure:The amount of air inside the tire
pressing outward on each square inch of the
tire. Air pressure is expressed in pounds
per square inch (psi) or kilopascal (kPa).
Accessory Weight:This means the combined
weight of optional accessories. Some examples of
optional accessories are, automatic
transmission/transaxle, power steering, power
brakes, power windows, power seats, and
air conditioning.
Aspect Ratio:The relationship of a tire’s height
to its width.
Belt:A rubber coated layer of cords that is
located between the plies and the tread. Cords
may be made from steel or other reinforcing
materials.
Bead:The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the rim.
Bias Ply Tire:A pneumatic tire in which the plies
are laid at alternate angles less than 90 degrees
to the centerline of the tread.
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Cold Tire Pressure:The amount of air pressure
in a tire, measured in pounds per square inch
(psi) or kilopascals (kPa) before a tire has built up
heat from driving. SeeInation - Tire Pressure
on page 431.
Curb Weight:This means the weight of a motor
vehicle with standard and optional equipment
including the maximum capacity of fuel, oil, and
coolant, but without passengers and cargo.
DOT Markings:A code molded into the sidewall
of a tire signifying that the tire is in compliance
with the U.S. Department of Transportation (DOT)
motor vehicle safety standards. The DOT code
includes the Tire Identication Number (TIN),
an alphanumeric designator which can also identify
the tire manufacturer, production plant, brand,
and date of production.
GVWR:Gross Vehicle Weight Rating. See
Loading Your Vehicle on page 349.
GAWR FRT:Gross Axle Weight Rating for the
front axle. SeeLoading Your Vehicle on page 349.GAWR RR:Gross Axle Weight Rating for the rear
axle. SeeLoading Your Vehicle on page 349.
Intended Outboard Sidewall:The side of
an asymmetrical tire, that must always face
outward when mounted on a vehicle.
Kilopascal (kPa):The metric unit for air pressure.
Light Truck (LT-Metric) Tire:A tire used on
light duty trucks and some multipurpose passenger
vehicles.
Load Index:An assigned number ranging from
1 to 279 that corresponds to the load carrying
capacity of a tire.
Maximum Ination Pressure:The maximum air
pressure to which a cold tire may be inated.
The maximum air pressure is molded onto
the sidewall.
Maximum Load Rating:The load rating for a tire
at the maximum permissible ination pressure
for that tire.
427

Maximum Loaded Vehicle Weight:The sum of
curb weight, accessory weight, vehicle capacity
weight, and production options weight.
Normal Occupant Weight:The number of
occupants a vehicle is designed to seat multiplied
by 150 lbs (68 kg). SeeLoading Your Vehicle
on page 349.
Occupant Distribution:Designated seating
positions.
Outward Facing Sidewall:The side of an
asymmetrical tire that has a particular side that
faces outward when mounted on a vehicle.
The side of the tire that contains a whitewall, bears
white lettering, or bears manufacturer, brand,
and/or model name molding that is higher
or deeper than the same moldings on the other
sidewall of the tire.
Passenger (P-Metric) Tire:A tire used on
passenger cars and some light duty trucks and
multipurpose vehicles.Recommended Ination Pressure:Vehicle
manufacturer’s recommended tire ination
pressure as shown on the tire placard. See
Ination - Tire Pressure on page 431andLoading
Your Vehicle on page 349.
Radial Ply Tire:A pneumatic tire in which the ply
cords that extend to the beads are laid at 90
degrees to the centerline of the tread.
Rim:A metal support for a tire and upon which
the tire beads are seated.
Sidewall:The portion of a tire between the tread
and the bead.
Speed Rating:An alphanumeric code assigned
to a tire indicating the maximum speed at
which a tire can operate.
Traction:The friction between the tire and the
road surface. The amount of grip provided.
Tread:The portion of a tire that comes into
contact with the road.
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Treadwear Indicators:Narrow bands, sometimes
called wear bars, that show across the tread of a
tire when only 1/16 inch (1.6 mm) of tread remains.
SeeWhen It Is Time for New Tires on page 440.
UTQGS (Uniform Tire Quality Grading
Standards):A tire information system that
provides consumers with ratings for a tire’s
traction, temperature, and treadwear. Ratings are
determined by tire manufacturers using
government testing procedures. The ratings are
molded into the sidewall of the tire. SeeUniform
Tire Quality Grading on page 444.
Vehicle Capacity Weight:The number of
designated seating positions multiplied by 150 lbs
(68 kg) plus the rated cargo load. SeeLoading
Your Vehicle on page 349.
Vehicle Maximum Load on the Tire:Load on an
individual tire due to curb weight, accessory
weight, occupant weight, and cargo weight.
Vehicle Placard:A label permanently attached to
a vehicle showing the vehicle’s capacity weight
and the original equipment tire size and
recommended ination pressure. See “Tire and
Loading Information Label” underLoading
Your Vehicle on page 349.Run-Flat Tires (STS-V)
If your vehicle has run-at tires, there is no spare
tire and no tire changing equipment. Your
vehicle also has a Tire Pressure Monitor
System (TPMS) which will alert you if there is a
loss of tire pressure in any of the tires. See
Tire Pressure Monitor System on page 433.
{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.
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If a tire goes at, you will not need to stop on the
side of the road to change the tire. You can
just keep on driving. The vehicle’s run-at tires
can operate effectively with no air pressure for up
to 50 miles (80 km) at speeds up to 55 mph
(90 km/h). The shorter the distance you drive and
the slower the speed, the greater the chance
that the tire will not have to be replaced. When a
tire is lled with air, it provides a cushion
between the road and the wheel. Because you will
not have this cushion when driving on a deated
run-at tire, try to avoid potholes that could
damage your wheel and require replacement of it.
Some road hazards can damage a tire beyond
repair. This damage could occur even before you
have driven on the tire in a deated condition.
When a tire has been damaged, or if you have
driven any distance on a deated run-at tire, check
with an authorized run-at tire service center, as
soon as possible, to determine whether the tire can
be repaired or should be replaced. To maintain your
vehicle’s run-at feature, all replacement tires must
be self-supporting tires. To locate the nearest GM
or authorized run-at servicing facility, call
Roadside Service. SeeRoadside Service on
page 531for details.
{CAUTION:
Run-at tires are constructed differently
than other tires and could explode during
improper service. You or others could be
injured or killed if you attempt to repair,
replace, dismount, or mount a run-at tire.
Let only an authorized run-at service
center repair, replace, dismount, and
mount run-at tires.
The valve stems on your vehicle’s run-at tires
have sensors that are part of the Tire Pressure
Monitor System (TPMS). These sensors contain
batteries which are designed to last for 10 years
under normal driving conditions. See your GM
dealer, if the TPMS sensors or a wheel ever need
replacement.
Notice:Using liquid sealants can damage the
tire valves and tire pressure monitor sensors in
your vehicle’s run-at tires. This damage would
not be covered by warranty. Do not use liquid
sealants in your vehicle’s run-at tires.
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