tire pressure CHEVROLET TRACKER 2004 2.G User Guide

(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 5-63andLoading Your
Vehicle on page 4-51.
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
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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. Light Truck (LT-Metric) Tire
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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 In¯ation Pressure:The amount of air pressure in
a tire, measured in pounds per square inch (psi) or
kilopascals (kPa) before a tire has built up heat
from driving. See
In¯ation - Tire Pressure on page 5-63.
Curb Weight:This means the weight of a motor
vehicle with standard and optional equipment including
the maximum capacity of fuel, oil and coolant, but
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 4-51.GAWR FRT:Gross Axle Weight Rating for the front
axle, see
Loading Your Vehicle on page 4-51.
GAWR RR:Gross Axle Weight Rating for the rear axle,
see
Loading Your Vehicle on page 4-51.
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.
Load Index:An assigned number ranging
from 1 to 279 that corresponds to the load
carrying capacity of a tire.
Maximum In¯ation Pressure:The maximum air
pressure to which a cold tire may be in¯ated. The
maximum air pressure is molded onto the sidewall.
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.
5-61

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 4-51.
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 and
shown on the tire placard. See
In¯ation - Tire Pressure
on page 5-63andLoading Your Vehicle on page 4-51.
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 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 5-66.
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 5-68.
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 4-51.
Vehicle Maximum Load on the Tire:Load on an
individual tire due to curb weight, accessory weight,
occupant weight and cargo weight.
5-62

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 4-51.
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 4-51, 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 economyIf 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.
5-63

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.
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 5-66andWheel Replacement
on page 5-70for 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 6-4.
5-64

When rotating your tires, always use one of the correct
rotation patterns shown here.
After the tires have been rotated, adjust the front and
rear in¯ation pressures as shown on the tire and loading
information label. See
Loading Your Vehicle on
page 4-51, for information on the tire and loading
information label and its location on your vehicle. Make
certain that all wheel nuts are properly tightened.
See ªWheel Nut Torqueº under
Capacities and
Speci®cations on page 5-98.
{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.
5-65

Buying New Tires
To ®nd out what kind and size of tires you need, look at
the Tire and Loading Information label. For information
about this label and where to ®nd it, see
Loading
Your Vehicle on page 4-51.
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, 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).
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
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.
{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.
5-67

qDrain, ¯ush and re®ll cooling system (or every
30 months, whichever occurs ®rst). SeeEngine
Coolant on page 5-25for what to use. Inspect hoses.
Clean radiator, condenser, pressure cap and neck.
Pressure test the cooling system and pressure
cap.
An Emission Control Service. (See footnote ².)
qInspect ignition coil plug cap (or every 30 months,
whichever occurs ®rst).An Emission Control
Service. (See footnote ².)
qReplace engine air cleaner ®lter. SeeEngine Air
Cleaner/Filter on page 5-18for more information.An Emission Control Service.
qChange automatic transmission ¯uid and ®lter if the
vehicle is mainly driven under one or more of these
conditions:
þ In heavy city traffic where the outside
temperature regularly reaches 90ÉF (32ÉC) or
higher.
þ In hilly or mountainous terrain.
þ When doing frequent trailer towing.
þ Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change the ¯uid and ®lter every
100,000 miles (166 000 km).
qRotate tires. SeeTire Inspection and Rotation on
page 5-64for proper rotation pattern and additional
information.(See footnote +.)
qChange manual transmission ¯uid.
qChange transfer case ¯uid.
qChange differential ¯uid.
qReplace fuel ®lter (or every 30 months, whichever
occurs ®rst, or sooner if ®lter is clogged).
An
Emission Control Service. (See footnote ².)
qInspect propeller shafts and U-joints for looseness
and damage (or every 15 months, whichever
occurs ®rst). Inspect more frequently if used off-road
or for pulling a trailer. Tighten U-joint ¯ange bolts
if necessary.
33,000 Miles (55 000 km)
qChange engine oil and ®lter (or every 3 months,
whichever occurs ®rst).An Emission Control Service.
6-10

If you do not use your vehicle under any of these
conditions, change the ¯uid and ®lter every
100,000 miles (166 000 km).
qInspect engine accessory drive belts (or every
30 months, whichever occurs ®rst).An Emission
Control Service.
qDrain, ¯ush and re®ll cooling system (or every
30 months, whichever occurs ®rst). SeeEngine
Coolant on page 5-25for what to use. Inspect hoses.
Clean radiator, condenser, pressure cap and neck.
Pressure test the cooling system and pressure
cap.
An Emission Control Service. (See footnote ².)
qReplace spark plugs.An Emission Control Service.
qInspect ignition coil plug cap (or every 30 months,
whichever occurs ®rst).An Emission Control
Service.
qDrain, re®ll and bleed the brake system.
qInspect fuel tank, cap and lines for damage or leaks.
Inspect fuel cap gasket for any damage. Replace
parts as needed.
An Emission Control Service.
(See footnote ².)
qReplace engine air cleaner ®lter. SeeEngine Air
Cleaner/Filter on page 5-18for more information.An Emission Control Service.
qRotate tires. SeeTire Inspection and Rotation on
page 5-64for proper rotation pattern and additional
information.(See footnote +.)
qReplace fuel ®lter (or every 30 months, whichever
occurs ®rst).An Emission Control Service.
(See footnote ².)
qChange manual transmission ¯uid.
qChange transfer case ¯uid.
qChange differential ¯uid.
qInspect emission system hoses and replace as
necessary.
An Emission Control Service.
(See footnote ².)
qInspect propeller shafts and U-joints for looseness
and damage (or every 15 months, whichever
occurs ®rst). Inspect more frequently if used off-road
or for pulling a trailer. Tighten U-joint ¯ange bolts
if necessary.
63,000 Miles (105 000 km)
qChange engine oil and ®lter (or every 3 months,
whichever occurs ®rst).An Emission Control Service.
66,000 Miles (110 000 km)
qChange engine oil and ®lter (or every 3 months,
whichever occurs ®rst).An Emission Control Service.
qIf Equipped: Inspect passenger compartment
air ®lters.
qRotate tires. See
Tire Inspection and Rotation on
page 5-64for proper rotation pattern and additional
information.(See footnote +.)
6-13