2004 PONTIAC VIBE Owners Manual

A. Tire Size
B. Department of Transportation (DOT)
C. Tire Identi®cation Number (TIN)
D. Tire Ply Material
E. Uniform Tire Quality Grading (UTQG)
F. Maximum Cold In¯ation Load Limit
Tire Size:The tire size 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.
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.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.
Tire Ply Material:The type of cord and number of plies
in the sidewall and under the tread.
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 5-72.
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 Ð Tire
Pressure on page 5-67andLoading Your Vehicle on
page 4-32.
5-63

Tire Size
The following illustration shows an example of a typical
passenger car tire size.
A. Passenger (P-Metric) Tire
B. Tire Width
C. Aspect Ratio
D. Belt Rating
E. Rim Diameter
F. Load Range
G. Speed RatingPassenger (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.
Tire Width:The three-digit number indicates the tire
section width in millimeters from sidewall to sidewall.
Aspect Ratio:A two-digit number that indicates the tire
height-to-width measurements. For example, if the
tire size aspect ratio is ª70,º as shown in item ªCº of the
illustration, it would mean that the tire's sidewall is
70% as high as it is wide.
Belt Rating: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.
Rim Diameter:Diameter of the wheel in inches.
Load Range:The load range represents the load carry
capacity a tire is certi®ed to carry.
Speed Rating:The maximum speed that a tire
is certi®ed to carry a load. Speed ratings range
from ªAº to ªZº.
5-64

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, for example, automatic
transmission, power steering, power brakes, power
windows, power seats, radio 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 that hold the
tire onto the rim.
Bias Ply Tire:A pneumatic tire in which the ply cords
that extend to the beads are laid at alternate angles
substantially less than 90 degrees to the centerline of
the tread.
Cold In¯ation Pressure:The amount of air pressure in
a tire, measured in pounds per square inch (psi) or
kilopascal (kPa), before a tire has built up heat
from driving. See
In¯ation -- Tire Pressure on page 5-67.Curb Weight:This means the weight of a motor
vehicle with standard and optional equipment including
the maximum capacity of fuel, oil and coolant, without
passengers and cargo.
DOT Markings:A code molded into the sidewall of a
tire signifying that the tire is in compliance with the
U.S. Department of Transportation motor vehicle safety
standards. The DOT code includes the Tire Identi®cation
Number (TIN), an alphanumeric designator which can
also identify the tire manufacturer, production plant,
brand and date of production.
GVWR:Gross Vehicle Weight Rating, see
Loading
Your Vehicle on page 4-32.
GAWR FRT:Gross Axle Weight Rating for the front
axle, see
Loading Your Vehicle on page 4-32.
GAWR RR:Gross Axle Weight Rating for the rear axle,
see
Loading Your Vehicle on page 4-32.
Intended Outboard Sidewall:The side of an
asymmetrical tire that must always face outward when
mounted on a vehicle.
Kilopascal (kPa):The metric unit for air pressure.
There are 6.9 kPa's to one psi.
Light Truck (LT-Metric) Tire:A tire used on light duty
trucks and some multipurpose passenger vehicles.
5-65

Load Index:An assigned number ranging from 1 to
279 that corresponds to the load carrying capacity of
a tire.
Maximum Load Rating:The load rating for a tire at
the maximum permissible in¯ation pressure for that tire.
Maximum Loaded Vehicle Weight:The sum of
curb weight; accessory weight; vehicle capacity weight;
and production options weight.
Maximum Permissible In¯ation Pressure:The
maximum cold in¯ation pressure to which a tire may
be in¯ated.
Normal Occupant Weight:The number of occupants a
vehicle is designed to seat multiplied by 150 pounds
(68 kg). See
Loading Your Vehicle on page 4-32.
Occupant Distribution:Designated seating positions.
Outward Facing Sidewall:The side of a asymmetrical
tire that has a particular side that faces outward
when mounted on a vehicle. The side of the tire that
contains a whitewall, bears white lettering or bears
manufacturer, brand and or model name molding that is
higher or deeper than the same moldings on the
other sidewall of the tire.Passenger (P-Metric) Tire:A tire used on passenger
cars and some light duty trucks and multipurpose
vehicles.
Recommended In¯ation Pressure:Vehicle
manufacturer's recommended tire in¯ation pressure
shown on the tire placard. See
In¯ation -- Tire Pressure
on page 5-67andLoading Your Vehicle on page 4-32.
Radial Ply tire:A pneumatic tire in which the ply cords
that extend to the beads are laid at substantially
90 degrees to the centerline of the tread.
Rim:A metal support for a tire or a tire and tube
assembly 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.
Treadwear Indicators:Narrow bands, sometimes
called ªwear bars,º that show across the tread of a tire
when only 2/32 inch of tread remains. See
When It
Is Time for New Tires on page 5-70.
5-66

Tread Width:The width of the tire's tread.
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. See
Uniform Tire Quality
Grading on page 5-72.
Vehicle Capacity Weight:Is the number of designated
seating positions multiplied by 150 pounds (68 kg)
plus the rated cargo load. See
Loading Your Vehicle
on page 4-32
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 original equipment tire size and
the recommended cold in¯ation pressure. See
Loading
Your Vehicle on page 4-32.
In¯ation Ð 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 4-32.
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 to Check
Check your tires once a month or more.
Don't forget your compact spare tire. It should be
at 60 psi (420 kPa).
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.
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 in¯ation 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.
Tire Inspection and Rotation
Tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km).
Any time you notice unusual wear, rotate your tires as
soon as possible and check wheel alignment. Also
check for damaged tires or wheels. See
When It Is Time
for New Tires on page 5-70andWheel Replacement
on page 5-74for more information.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The ®rst rotation
is the most important. See
Part A: Scheduled
Maintenance Services on page 6-4for scheduled
rotation intervals.
5-68

When rotating your tires, always use the correct rotation
pattern shown here.
Tires should only be moved from front to rear and rear
to front on the same side of the vehicle.
Don't include the compact spare tire in your tire rotation.After the tires have been rotated, adjust the front and
rear in¯ation pressures as shown on the Tire and
Loading Information label. Make certain that all wheel
nuts are properly tightened. See ªWheel Nut Torqueº
under
Capacities and Speci®cations on page 5-101.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after a time. The wheel could
come off and cause an accident. When you
change a wheel, remove any rust or dirt from
places where the wheel attaches to the vehicle.
In an emergency, you can use a cloth or a
paper towel to do this; but be sure to use a
scraper or wire brush later, if you need to, to
get all the rust or dirt off. See ªChanging a Flat
Tireº in the Index.
5-69

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.
5-70