tire size Oldsmobile Silhouette 2004 Owner's Manuals

All-Wheel Drive Disable Warning
Message
Your vehicle may have this message. If it does, it will
come on when there is a spare tire on the vehicle, or
when the anti-lock brake system warning light comes on,
or when the rear differential ¯uid is overheating. This
message will go out when the differential ¯uid cools.
The all-wheel drive system will be disabled until the
compact spare tire is replaced by a full-size tire. If the
warning message is still on after putting on the full-size
tire, you need to reset the warning message. To reset the
warning message, turn the ignition off and then back on
again. If the message stays on, see your dealer right
away. See
All-Wheel Drive (AWD) System on page 4-10for more information.
Low Fuel Warning Message
If your fuel is low, the warning message will come on
and stay on until you add fuel.
If the warning message is still on after adding fuel,
you need to reset the warning message. To reset the
warning message, turn the ignition off and then back on.
If the message stays on, see your dealer. United StatesCanada
United StatesCanada
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The Tire and Loading Information label also tells you
the size and recommended in¯ation pressure for
the original equipment tires on your vehicle. For more
information on tires and in¯ation, see
Tires on page 5-58andIn¯ation - Tire Pressure on page 5-67.
If your vehicle does not have the Tire and Loading
Information label, the Certi®cation/Tire label shows the
tire size and recommended in¯ation pressures
needed to obtain the Gross Vehicle Weight Rating
(GVWR) and the Gross Axle Weight Rating (GAWR) for
the front and rear axles. See ªCerti®cation/Tire Labelº
later in this section.
Steps for Determining Correct Load Limit
1. Locate the statement ªThe combined weight of
occupants and cargo should never exceed XXX
poundsº on your vehicle placard.
2. Determine the combined weight of the driver and
passengers that will be riding in your vehicle.
3. Subtract the combined weight of the driver and
passengers from XXX kilograms or XXX pounds.4. The resulting ®gure equals the available amount of
cargo and luggage load capacity. For example, if the
ªXXXº amount equals 1400 lbs. and there will be
®ve 150 lb. passengers in your vehicle, the amount
of available cargo and luggage load capacity is
650 lbs. (1400-750 (5 x 150) = 650 lbs.).
5. Determine the combined weight of luggage and
cargo being loaded on the vehicle. That weight
may not safely exceed the available cargo
and luggage load capacity calculated in Step 4.
6. If your vehicle will be towing a trailer, the load from
your trailer will be transferred to your vehicle.
Consult this manual to determine how this reduces
the available cargo and luggage load capacity
for your vehicle.
See
Towing a Trailer on page 4-38for important
information on towing a trailer, towing safety rules, and
trailering tips.
4-34

The label shows the size of your original tires and the
in¯ation pressures needed to obtain the gross weight
capacity of your vehicle. This is called the Gross Vehicle
Weight Rating (GVWR). The GVWR includes the
weight of the vehicle, all occupants, fuel, and cargo.
The Certi®cation/Tire label also tells you the maximum
weights for the front and rear axles, called the Gross
Axle Weight Rating (GAWR). To ®nd out the actual loads
on your front and rear axles, you need to go to a
weigh station and weigh your vehicle. Your dealer can
help you with this. Be sure to spread out your load
equally on both sides of the centerline.
Never exceed the GVWR for your vehicle or the GAWR
for either the front or rear axle.
{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.
Notice:Overloading your vehicle may cause
damage. Repairs would not be covered by your
warranty. Do not overload your vehicle.
If you put things inside your vehicle Ð like suitcases,
tools, packages, or anything else Ð they will go as fast
as the vehicle goes. If you have to stop or turn
quickly, or if there is a crash, they will keep going.
{CAUTION:
Things you put inside your vehicle can strike
and injure people in a sudden stop or turn, or
in a crash.
·Put things in the cargo area of your
vehicle. Try to spread the weight evenly.
·Never stack heavier things, like suitcases,
inside the vehicle so that some of them
are above the tops of the seats.
·Do not leave an unsecured child restraint
in your vehicle.
·When you carry something inside the
vehicle, secure it whenever you can.
·Do not leave a seat folded down unless
you need to.
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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.
P-Metric Tire
5-59

(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 4-33.
(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.
(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 4-33.
5-61

(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. See
Compact Spare Tire on
page 5-91andIf a Tire Goes Flat on page 5-76.
(B) Tire Ply Material:The type of cord and number of
plies in the sidewall and under the tread.
(C) Tire Identi®cation Number (TIN):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.
(D) Maximum Cold In¯ation Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load. See
Compact Spare Tire
on page 5-91andLoading Your Vehicle on page 4-33.
(E) Tire In¯ation:The temporary use tire or compact
spare tire should be in¯ated to 60 psi (420 kPa).
For more information on tire pressure and in¯ation see
In¯ation - Tire Pressure on page 5-67.
Compact Spare Tire Example
5-62

(F) Tire Size:A combination of letters and numbers
de®ne a tire's width, height, aspect ratio, construction
type and service description. The letter ªTº as the
®rst character in the tire size means the tire is for
temporary use only.
(G) 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.
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. The light truck tire size example
above shows dual or single tire con®gurations.
Passenger (P-Metric) Tire
5-63

(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. Light Truck (LT-Metric) Tire
5-64

Vehicle Capacity Weight:The number of designated
seating positions multiplied by 150 lbs. (68 kg) plus
the rated cargo load. See
Loading Your Vehicle
on page 4-33.
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 original equipment tire size
and recommended in¯ation pressure. See
Loading
Your Vehicle on page 4-33.
In¯ation - Tire Pressure
The Certi®cation/Tire label or 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 4-33.
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
5-67

When It Is Time for New Tires
One way to tell when it's
time for new tires is to
check the treadwear
indicators, which will
appear when your tires
have only 1/16 inch
(1.6 mm) or less of
tread remaining.
You need a new tire if any of the following statements
are true:
·You can see the indicators at three or more places
around the tire.
·You can see cord or fabric showing through the
tire's rubber.
·The tread or sidewall is cracked, cut or snagged
deep enough to show cord or fabric.
·The tire has a bump, bulge or split.
·The tire has a puncture, cut or other damage that
can't be repaired well because of the size or
location of the damage.
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 4-33, for examples of the 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®cation (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, traction, ride 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).
If you ever 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.
5-70