2004 CHEVROLET CORVETTE tire size

The Tire and Loading Information label also gives you
the size and recommended inflation pressure for
the factory-installed, original equipment tires on your
vehicle. For more information on tires and inflation see
Tires on page 5-55andInation - Tire Pressure on
page 5-62.
There is also important loading information on the
Certification label. It tells you the Gross Vehicle Weight
Rating (GVWR) and the Gross Axle Weight Rating
(GAWR) for the front and rear axle; see “Certification
Label” later in this section.
Steps for Determining Correct Load Limit
1. Locate the statement “The combined weight of
occupants and cargo should never exceed XXX
pounds” 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 figure equals the available amount of
cargo and luggage load capacity. For example, if the
“XXX” amount equals 1400 lbs. and there will be five
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 of
your vehicle.
Your vehicle is neither designed nor intended to tow
a trailer.
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A. Tire Size
B. Tire Performance Criteria Specification (TPC Spec)
C. Department of Transportation (DOT)
D. Tire Identification Number (TIN)
E. Tire Ply Material
F. Uniform Tire Quality Grading (UTQG)
G. Maximum Cold Inflation Load Limit
(A) Tire Size:The tire size code is a combination of
letters and numbers used to define 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) Tire Performance Criteria Specication (TPC
Spec):Original equipment tires designed to GM’s
specific tire performance criteria have a TPC
specification code molded onto the sidewall. GM’s TPC
specifications 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.
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(D) Tire Identication Number (TIN):The letters and
numbers following DOT code are the Tire Identification
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 5-67.
(G) Maximum Cold Ination Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load. For more information on
recommended tire pressure seeInation - Tire Pressure
on page 5-62andLoading Your Vehicle on page 4-33.Tire Size Codes
The following illustration shows an example of a typical
passenger car tire size.
A. P-Metric Tire
B. Tire Width
C. Aspect RatioD. Construction Code
E. Rim Diameter
F. Service Description
(A) P-Metric Tire:The United States version of a
metric tire sizing system. The letter “P” as the
first 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 “70,” as shown in item “C” of
the illustration, it would mean that the tire’s sidewall
is 70% 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 the speed rating of a tire. The
load range represents the load carrying capacity a tire is
certified to carry. The load index can range from 1 to
279. The speed rating is the maximum speed a tire
is certified 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.
Cold Ination Pressure:The amount of air pressure
in a tire, measured in pounds per square inch (psi)
before a tire has built up heat from driving.
SeeInation - Tire Pressure on page 5-62.
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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 inflation pressure and
shown on the tire placard. SeeInation - Tire Pressure
on page 5-62andLoading Your Vehicle on page 4-33.
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.Treadwear Indicators:Narrow bands, sometimes
called “wear bars,” that show across the tread of a tire
when only 2/32 inch of tread remains. SeeWhen It
Is Time for New Tires on page 5-65.
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 5-67.
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 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 inflation pressure. SeeLoading Your
Vehicle on page 4-33.
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The valve stems on your extended mobility tires have
sensors that are part of the Tire Pressure Monitor
(TPM). SeeTire Pressure Monitor Operation
(Except Z06) on page 5-64. The TPM sensors contain
batteries which are designed to last for 10 years
under normal driving conditions. See your dealer if you
ever need to have a wheel replaced, or if the sensors
ever need replacement.
Notice:Using liquid sealants can damage the tire
valves and tire pressure monitor sensors in your
extended mobility tires. This damage would not be
covered by warranty. Don’t use liquid sealants
in your extended mobility tires.
If you feel that winter tires are needed for your driving
conditions, Goodyear Eagle M+S EMT tires are available
in your original equipment sizes from an authorized
Goodyear EMT retailer. These tires will improve snow
traction while maintaining your vehicle’s extended
mobility feature. When using winter tires on your vehicle,
be sure to use them on all four wheels. SeeBuying
New Tires on page 5-66.Ination - Tire Pressure
The tire and loading information label, shows the correct
inflation pressures for your tires when they’re cold.
“Cold” 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, for the location
of your vehicle’s tire and loading information label.
Notice:Don’t let anyone tell you that underination
or overination is all right. It’s not. If your tires
don’t have enough air (underination), 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 (overination), you
can get the following:
Unusual wear
Bad handling
Rough ride
Needless damage from road hazards
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If a tire pressure message appears on the Driver
Information Center, stop as soon as you can. Have the
tire pressures checked and set to those shown on
your Tire-Loading Information label. SeeInation - Tire
Pressure on page 5-62.
{CAUTION:
When the LOW TIRE PRESSURE or FLAT TIRE
message is displayed on the Driver Information
Center, 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. Don’t
drive over 55 mph (90 km/h) when the LOW
TIRE PRESSURE or FLAT TIRE message is
displayed. Drive cautiously, and check your
tire pressures as soon as you can.
Tire Rotation
The tires on your vehicle are different sizes front to rear.
Due to this, your tires should not be rotated. Each tire
and wheel should be used only in the position it is in.
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.
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Buying New Tires
To find out what kind and size of tires your vehicle
needs, look at the Tire and Loading Information label.
SeeLoading Your Vehicle on page 4-33, for an example
of the label and where it is located on your vehicle.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Specification (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, load range, speed rating, 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 “MS” (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.{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different sizes
(other than those originally installed on your
vehicle) or types (radial and bias-belted tires),
the vehicle may not handle properly, and you
could have a crash. Using tires of different
sizes (other than those originally installed on
your vehicle) may also cause damage to your
vehicle. Be sure to use the correct size and
type tires on all four wheels.
If your vehicle is equipped with Extended Mobility Tires
and you feel that winter tires are needed, see
Extended Mobility Tires (Except Z06) on page 5-61.
{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.
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