tire type BUICK RANDEZVOUS 2007 Owner's Manual

Page 316 of 528

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,
your 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.
A cornering skid is best handled by easing your
foot off the accelerator pedal.
If you have the Traction Control System (TCS),
remember: It helps avoid only the acceleration
skid. SeeTraction Control System (TCS) on
page 310. If you do not have this system, or if the
system is off, then an acceleration skid is also
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.
316

Page 407 of 528

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
407

Page 408 of 528

(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 see
Uniform Tire Quality Grading on page 420.
(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 450andIf a Tire Goes Flat on
page 427.
Compact Spare Tire Example
408

Page 409 of 528

(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 413.
(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.
409

Page 410 of 528

(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.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.
410

Page 414 of 528

When to Check
Check your tires once a month or more. Do not
forget to check the compact spare tire, it should be
at 60 psi (420 kPa). For additional information
regarding the compact spare tire, seeCompact
Spare Tire on page 450.
How to Check
Use a good quality pocket-type gage to check tire
pressure. You cannot tell if your tires are properly
inated simply by looking at them. Radial tires
may look properly inated even when they are
under-inated. Check the tire’s ination pressure
when the tires are cold. Cold means your vehicle
has been sitting for at least three hours or driven no
more than 1 mile (1.6 km).
Remove the valve cap from the tire valve stem.
Press the tire gage rmly onto the valve to
get a pressure measurement. If the cold tire
ination pressure matches the recommended
pressure on the Tire and Loading Information
label, no further adjustment is necessary. If the
ination pressure is low, add air until you reach
the recommended amount.If you overll the tire, release air by pushing on
the metal stem in the center of the tire valve.
Re-check the tire pressure with the tire gage.
Be sure to put the valve caps back on the valve
stems. They help prevent leaks by keeping out dirt
and moisture.
Check Tire Pressure System
Your vehicle may have a check tire pressure
system that can alert you to a large change in the
pressure of one tire. The system won’t alert you
before you drive that a tire is low or at. You must
begin driving before the system will work properly.
The LOW TIRE PRESSURE HOLD SET TO
RESET message will appear on the Driver
Information Center (DIC) and the LOW TIRE
PRESSURE message will come on the message
center if pressure difference, or low pressure, is
detected in one tire. In the following conditions, the
LOW TIRE PRESSURE message may not come on
even if the tire pressure is low, or it may come on
when the tire pressure is actually normal:
More than one tire is low
Only one tire is replaced with a new tire during
service
414

Page 419 of 528

If the tires have an all-season tread design, the
TPC spec number will be followed by an MS
for mud and snow. SeeTire Sidewall Labeling
on page 407for additional information.
{CAUTION:
Mixing tires could cause you to lose
control while driving. If you mix tires of
different sizes, 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,
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 compact
spare temporarily, as it was developed for
use on your vehicle. SeeCompact Spare
Tire on page 450.
{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.
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).
SeeLoading Your Vehicle on page 332, for more
information about the Tire and Loading Information
Label and its location on your vehicle.
419

Page 420 of 528

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 418and
Accessories and Modications on page 354
for 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.
420

Page 424 of 528

Tire Chains
{CAUTION:
Do not use tire chains. 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
the wheels. If you do nd traction devices
that will t, install them on the front tires
for front-wheel-drive vehicles. If your
vehicle has all-wheel drive, install traction
devices on either the front tires or all four
tires, but never on the rear tires only.
424