2009 CADILLAC SRX tire type

Skidding
In a skid, a driver can lose control of the vehicle.
Defensive drivers avoid most skids by taking reasonable
care suited to existing conditions, and by not overdriving
those conditions. But skids are always possible.
The three types of skids correspond to your vehicle’s
three control systems. In the braking skid, the wheels are
not rolling. In the steering or cornering skid, too much
speed or steering in a curve causes tires to slip and lose
cornering force. And in the acceleration skid, too much
throttle causes the driving wheels to spin.
Remember: Any traction control system helps avoid only
the acceleration skid. If your traction control system is
off, then an acceleration skid is best handled by
easing your foot off the accelerator pedal.
If your vehicle starts to slide, ease your foot off the
accelerator pedal and quickly steer the way you want the
vehicle to go. If you start steering quickly enough, your
vehicle may straighten out. Always be ready for a second
skid if it occurs.
Of course, traction is reduced when water, snow, ice,
gravel, or other material is on the road. For safety, you
will want to slow down and adjust your driving to these
conditions. It is important to slow down on slippery
surfaces because stopping distance will be longer and
vehicle control more limited.While driving on a surface with reduced traction, try
your best to avoid sudden steering, acceleration, or
braking, including reducing vehicle speed by shifting to a
lower gear. Any sudden changes could cause the tires to
slide. You may not realize the surface is slippery until
your vehicle is skidding. Learn to recognize warning
clues — such as enough water, ice, or packed snow on
the road to make a mirrored surface — and slow down
when you have any doubt.
Remember: Any Antilock Brake System (ABS) helps
avoid only the braking skid.
Off-Road Driving
Vehicles with all-wheel drive can be used for off-road
driving. Vehicles without all-wheel drive should not
be driven off-road except on a level, solid surface.
Many of the vehicle design features that help make the
vehicle more responsive on paved roads during poor
weather conditions also help make it better suited for
off-road use than conventional passenger vehicles.
The vehicle does not have features usually thought to
be necessary for extended or severe off-road use such
as special underbody shielding and transfer case low
gear range.
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Driving in Rain and on Wet Roads
Rain and wet roads can reduce vehicle traction and affect
your ability to stop and accelerate. Always drive slower
in these types of driving conditions and avoid driving
through large puddles and deep-standing or owing
water.
{CAUTION:
Wet brakes can cause crashes. They might not
work as well in a quick stop and could cause pulling
to one side. You could lose control of the vehicle.
After driving through a large puddle of water or a
car/vehicle wash, lightly apply the brake pedal until
the brakes work normally.
Flowing or rushing water creates strong forces.
Driving through owing water could cause your
vehicle to be carried away. If this happens, you and
other vehicle occupants could drown. Do not ignore
police warnings and be very cautious about trying to
drive through owing water.
Hydroplaning
Hydroplaning is dangerous. Water can build up under
your vehicle’s tires so they actually ride on the water.
This can happen if the road is wet enough and you are
going fast enough. When your vehicle is hydroplaning, it
has little or no contact with the road.
There is no hard and fast rule about hydroplaning.
The best advice is to slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet weather driving tips
include:
Allow extra following distance.
Pass with caution.
Keep windshield wiping equipment in good shape.
Keep the windshield washer uid reservoir lled.
Have good tires with proper tread depth. SeeTires
on page 5-48.
Turn off cruise control.
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It is important that the vehicle does not exceed any of its
ratings — GCWR, GVWR, RGAWR, Maximum Trailer
Rating or Tongue Weight. The only way to be sure it is
not exceeding any of these ratings is to weigh the vehicle
and trailer.
Total Weight on the Vehicle’s Tires
Be sure the vehicle’s tires are inated to the upper limit
for cold tires. These numbers can be found on the
Certication label or seeLoading the Vehicle on
page 4-30for more information. Make sure not to go
over the GVW limit for the vehicle, or the GAWR,
including the weight of the trailer tongue. If using a
weight distributing hitch, make sure not to go over the
rear axle limit before applying the weight distribution
spring bars.
Hitches
It is important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads are
a few reasons why the right hitch is needed.
The rear bumper on the vehicle is not intended
for hitches. Do not attach rental hitches or other
bumper-type hitches to it. Use only a frame-mounted
hitch that does not attach to the bumper.
Will any holes be made in the body of the vehicle
when the trailer hitch is installed? If so, be sure to
seal the holes when the hitch is removed. If they
are not sealed, deadly carbon monoxide (CO) from
the engine’s exhaust can get into the vehicle.
SeeEngine Exhaust on page 2-36. Sealing the
holes will also prevent dirt and water from entering
the vehicle.
Safety Chains
Always attach chains between the vehicle and the
trailer. Cross the safety chains under the tongue of
the trailer to help prevent the tongue from contacting
the road if it becomes separated from the hitch.
Instructions about safety chains may be provided by
the hitch manufacturer or by the trailer manufacturer.
Follow the manufacturer’s recommendation for
attaching safety chains and do not attach them to
the bumper. Always leave just enough slack so the
rig can turn. Never allow safety chains to drag on
the ground.
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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 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 5-66.
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.
(E) Tire Ply Material
:The type of cord and number
of plies in the sidewall and under the tread. Passenger (P-Metric) Tire Example
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(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 5-68.
(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, seeCompact
Spare Tire on page 5-88andIf a Tire Goes Flat on
page 5-73.
(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.
Compact Spare Tire Example
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(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 seeInflation - Tire Pressure on
page 5-56.
(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,
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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