tire type GMC SIERRA DENALI 2004 Owners Manual

Loss of Control
Let us review what driving experts say about what
happens when the three control systems (brakes,
steering and acceleration) do not have enough friction
where the tires meet the road to do what the driver
has asked.
In any emergency, do not give up. Keep trying to steer
and constantly seek an escape route or area of less
danger.
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
ªoverdrivingº 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 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 engine braking 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 Ð such as enough water, ice or packed snow
on the road to make a ªmirrored surfaceº Ð and slow
down when you have any doubt.
Remember: Any anti-lock brake system (ABS) helps
avoid only the braking skid.
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Towing
Towing Your Vehicle
Consult your dealer or a professional towing service if
you need to have your disabled vehicle towed. See
Roadside Assistance Program on page 7-6.
If you want to tow your vehicle behind another vehicle
for recreational purposes (such as behind a motorhome),
see ªRecreational Vehicle Towingº following.
Recreational Vehicle Towing
Recreational vehicle towing means towing your vehicle
behind another vehicle Ð such as behind a motorhome.
The two most common types of recreational vehicle
towing are known as ªdinghy towingº (towing your
vehicle with all four wheels on the ground) and ªdolly
towingº (towing your vehicle with two wheels on
the ground and two wheels up on a device known
as a ªdollyº).
Your vehicle was not designed to be towed with any of
its wheels on the ground. If your vehicle must be
towed, see
Towing Your Vehicle on page 4-48.
Notice:Towing an all-wheel-drive vehicle with all
four wheels on the ground, or even with only two of
its wheels on the ground, will damage drivetrain
components. Do not tow an all-wheel-drive vehicle if
any of its wheels will be on the ground.
Loading Your Vehicle
It is very important to know how much weight your
vehicle can carry. This weight is called the vehicle
capacity weight and includes the weight of all occupants,
cargo and all nonfactory-installed options. Two labels
on your vehicle show how much weight it may properly
carry, the Tire and Loading Information label and the
Certi®cation/Tire label.
{CAUTION:
Do not load your vehicle any heavier than the
GVWR, or either the maximum front or rear
GAWR. If you do, parts on your vehicle can
break, and it can change the way your vehicle
handles. These could cause you to lose
control and crash. Also, overloading can
shorten the life of your vehicle.
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(A) Tire Size Code:The tire size code is a combination
of letters and numbers used to de®ne a particular
tire's width, height, aspect ratio, construction type and
service description. See the ªTire Size Codeº illustration
later in this section for more detail.
(B) Tire Performance Criteria Speci®cation (TPC
Spec):Original equipment tires designed to GM's
speci®c tire performance criteria have a TPC
speci®cation code molded onto the sidewall. GM's TPC
speci®cations meet or exceed all federal safety
guidelines.
(C) Department of Transportation (DOT):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 Identi®cation Number (TIN):The letters and
numbers following DOT code are the Tire Identi®cation
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.
(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 5-71.
(G) Maximum Cold In¯ation Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load. For information on
recommended tire pressure see
In¯ation - Tire Pressure
on page 5-67andLoading Your Vehicle on page 4-48.
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(A) Tire Size:The tire size code is a combination of
letters and numbers used to de®ne a particular
tire's width, height, aspect ratio, construction type and
service description. See the ªTire Sizeº illustration
later in this section for more detail.
(B) Tire Performance Criteria Speci®cation (TPC
Spec):Original equipment tires designed to GM's
speci®c tire performance criteria have a TPC
speci®cation code molded onto the sidewall. GM's TPC
speci®cations meet or exceed all federal safety
guidelines.
(C) Dual Tire Maximum Load:Maximum load that can
be carried and the maximum pressure needed to
support that load when used in a dual con®guration. For
information on recommended tire pressure see
In¯ation - Tire Pressure on page 5-67andLoading Your
Vehicle on page 4-48.
(D) Department of Transportation (DOT):The
Department of Transportation (DOT) code indicates that
the tire is in compliance with the U.S. Department of
Transportation Motor Vehicle Safety Standards.
(E) Tire Identi®cation Number (TIN):The letters and
numbers following DOT code are the Tire Identi®cation
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.
LT-Metric Tire
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(F) Tire Ply Material:The type of cord and number of
plies in the sidewall and under the tread.
(G) Single Tire Maximum Load:Maximum load that
can be carried and the maximum pressure needed
to support that load when used as a single. For
information on recommended tire pressure see
In¯ation - Tire Pressure on page 5-67andLoading Your
Vehicle on page 4-48.
Tire Size
The following examples show the different parts of a
tire size.(A) Passenger (P-Metric) Tire:The United States
version of a metric tire sizing system. The letter ªPº 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.
(C) Aspect Ratio:A two-digit number that indicates
the tire height-to-width measurements. For example, if
the tire size aspect ratio is ª75,º as shown in item ªCº of
the illustration, it would mean that the tire's sidewall is
75% 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 ªRº means radial ply construction; the letter ªDº
means diagonal or bias ply construction; and the
letter ªBº means belted-bias ply construction.
(E) Rim Diameter:Diameter of the wheel in inches.
(F) Service Description:The service description
indicates the load range and speed rating of a tire.
The load index can range from 1 to 279. Speed ratings
range from ªAº to ªZº.
Passenger (P-Metric) Tire
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(A) Light Truck (LT-Metric) Tire:The United States
version of a metric tire sizing system. The letter ªLTº as
the ®rst two characters in the tire size means a light
truck 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.
(C) Aspect Ratio:A two-digit number that indicates
the tire height-to-width measurements. For example, if
the tire size aspect ratio is ª75,º as shown in item ªCº of
the illustration, it would mean that the tire's sidewall is
75% 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 ªRº means radial ply construction; the letter ªDº
means diagonal or bias ply construction; and the
letter ªBº means belted-bias ply construction.
(E) Rim Diameter:Diameter of the wheel in inches.
(F) Service Description:The service description
indicates the load range and speed rating of a tire.
The load index can range from 1 to 279. Speed ratings
range from ªAº to ªZº. The light truck tire size example
above shows dual or single tire con®gurations.Tire Terminology and De®nitions
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. Light Truck (LT-Metric) Tire
5-64

In¯ation - Tire Pressure
The tire and loading information label, shows the correct
in¯ation pressures for your tires when they're cold.
ªColdº means your vehicle has been sitting for at least
three hours or driven no more than 1 mile (1.6 km).
See
Loading Your Vehicle on page 4-48, for the location
of your vehicle's tire and loading information label.
Notice:Don't let anyone tell you that underin¯ation
or overin¯ation is all right. It's not. If your tires
don't have enough air (underin¯ation), you can get
the following:
·Too much ¯exing
·Too much heat
·Tire overloading
·Bad wear
·Bad handling
·Bad fuel economy
If your tires have too much air (overin¯ation), you
can get the following:
·Unusual wear
·Bad handling
·Rough ride
·Needless damage from road hazards
When to Check
Check your tires once a month or more.
Also, check the tire pressure of the spare tire.
How to Check
Use a good quality pocket-type gage to check tire
pressure. You can't tell if your tires are properly in¯ated
simply by looking at them. Radial tires may look
properly in¯ated even when they're underin¯ated. Check
the tire's in¯ation 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 in¯ation pressure matches
the recommended pressure on the tire and loading
information label, no further adjustment is necessary.
If the pressure is low, add air until you reach the
recommended amount.
If you over®ll the tire, release air by pushing on the
metal stem in the center of the tire valve. Recheck 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.
5-67

Buying New Tires
To ®nd out what kind and size of tires you need, look at
the Certi®cation/Tire label or the Tire and Loading
Information label. See
Loading Your Vehicle on
page 4-48, for more information about these labels and
where they can be found on your vehicle.
The tires installed on your vehicle when it was new
had a Tire Performance Criteria Speci®cations (TPC
Spec) number on each tire's sidewall. When you
get new tires, GM recommends that you get tires with
that same TPC Spec number. That way your vehicle will
continue to have tires that are designed to give proper
endurance, handling, speed rating, load range, traction,
ride, tire pressure monitoring system performance
and other things during normal service on your vehicle.
If your tires have an all-season tread design, the
TPC number will be followed by an ªMSº (for mud
and snow).
When ever you replace your tires with those not having
a TPC Spec number, make sure they are the same
size, load range, speed rating and construction
type (bias, bias-belted or radial) as your original tires.
{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different sizes
or types (radial and bias-belted tires), the
vehicle may not handle properly, and you
could have a crash. Using tires of different
sizes may also cause damage to your vehicle.
Be sure to use the same size and type tires on
all wheels.
Your vehicle may be equipped with a different
size spare than the road tires (those originally
installed on your vehicle). When new, your
vehicle included a spare tire and wheel
assembly with a similar overall diameter as
your vehicle's road tires and wheels, so it is all
right to drive on it. Because this spare was
developed for use on your vehicle, it will not
affect vehicle handling.
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{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.
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, 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
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 speci®ed 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 signi®cantly from the norm
due to variations in driving habits, service practices and
differences in road characteristics and climate.
5-71

Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You can't know how it's been used
or how far it's been driven. It could fail
suddenly and cause a crash. If you have to
replace a wheel, use a new GM original
equipment wheel.
Tire Chains
{CAUTION:
Don't use tire chains. There's 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's contacting your vehicle, and
don't spin your wheels. If you do ®nd traction
devices that will ®t, install them on the
rear tires.
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