2009 HUMMER H3 Owners Manual

CAUTION (Continued)
Underinated tires pose
the same danger as
overloaded tires. The
resulting accident could
cause serious injury.
Check all tires frequently to
maintain the recommended
pressure. Tire pressure
should be checked when
your vehicle’s tires are
cold. SeeInflation - Tire
Pressure on page 5-51.
Overinated tires are more
likely to be cut, punctured,
or broken by a sudden
impact — such as when
you hit a pothole. Keep
tires at the recommended
pressure.
Worn, old tires can cause
accidents. If the tire’s tread
is badly worn, or if your
vehicle’s tires have been
damaged, replace them.
Tire Sidewall Labeling
Useful information about a tire
is molded into the sidewall.
The following illustrations are
examples of a typical P-Metric
and a LT-Metric tire sidewall.
(A) Tire Size
:The tire size code
is a combination of letters and
numbers used to dene 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) TPC Spec (Tire
Performance Criteria
Specication)
:Original
equipment tires designed to
GM’s specic tire performance
criteria have a TPC specication
code molded onto the sidewall.
GM’s TPC specications meet
or exceed all federal safety
guidelines.
(C) DOT (Department of
Transportation)
:The
Department of Transportation
(DOT) code indicates that
the tire is in compliance
with the U.S. Department of
Transportation Motor Vehicle
Safety Standards.
Passenger (P-Metric) Tire
Service and Appearance Care 5-45

(D) Tire Identication Number
(TIN):The letters and numbers
following DOT code are the
Tire Identication 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,
seeUniform Tire Quality
Grading on page 5-62.(G) Maximum Cold Ination
Load Limit
:Maximum load that
can be carried and the maximum
pressure needed to support that
load. For information on
recommended tire pressure see
Inflation - Tire Pressure on
page 5-51andLoading the
Vehicle on page 4-35.
(A) Tire Size
:The tire size code
is a combination of letters and
numbers used to dene 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) TPC Spec (Tire
Performance Criteria
Specication)
:Original
equipment tires designed to
GM’s specic tire performance
criteria have a TPC specication
code molded onto the sidewall.
GM’s TPC specications 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
conguration. For information on
recommended tire pressure see
Inflation - Tire Pressure on
page 5-51andLoading the
Vehicle on page 4-35.
Light Truck (LT-Metric) Tire
5-46 Service and Appearance Care

(D) DOT (Department of
Transportation):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 Identication Number
(TIN)
:The letters and numbers
following DOT code are the
Tire Identication 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 seeInflation - Tire
Pressure on page 5-51and
Loading the Vehicle on
page 4-35.
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 P 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.
(A) Light Truck (LT-Metric)
Tire
:The United States version
of a metric tire sizing system.
The letters LT 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.
Passenger (P-Metric) Tire
Light Truck (LT-Metric) Tire
Service and Appearance Care 5-47

(C) Aspect Ratio:A two-digit
number that indicates the tire
height-to-width measurements.
For example, if the tire size
aspect ratio is 75, as shown
in item C of the light truck
(LT-Metric) tire illustration,
it would mean that the tire’s
sidewall is 75 percent 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
: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 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 Tire 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
Inflation - Tire Pressure on
page 5-51.
Curb Weight
: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.
5-48 Service and Appearance Care

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
(DOT) motor vehicle safety
standards. The DOT code
includes the Tire Identication
Number (TIN), an alphanumeric
designator which can also
identify the tire manufacturer,
production plant, brand, and date
of production.
GVWR
:Gross Vehicle Weight
Rating. SeeLoading the Vehicle
on page 4-35.
GAWR FRT
:Gross Axle
Weight Rating for the front axle.
SeeLoading the Vehicle on
page 4-35.
GAWR RR
:Gross Axle
Weight Rating for the rear axle.
SeeLoading the Vehicle on
page 4-35.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.
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 Ination Pressure
:The maximum air pressure
to which a cold tire can be
inated. The maximum air
pressure is molded onto the
sidewall.
Maximum Load Rating
:The load rating for a tire at the
maximum permissible ination
pressure for that tire.Maximum Loaded Vehicle
Weight
:The sum of curb
weight, accessory weight,
vehicle capacity weight, and
production options weight.
Normal Occupant Weight
:The number of occupants
a vehicle is designed to seat
multiplied by 150 lbs (68 kg).
SeeLoading the Vehicle
on page 4-35.
Occupant Distribution
:Designated seating positions.
Outward Facing Sidewall
:The side of an 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.
Service and Appearance Care 5-49

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 ination pressure as
shown on the tire placard.
SeeInflation - Tire Pressure on
page 5-51andLoading the
Vehicle on page 4-35.
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 1/16 inch
(1.6 mm) of tread remains.
SeeWhen It Is Time for New
Tires on page 5-58.
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 5-62.Vehicle Capacity Weight
:The number of designated
seating positions multiplied
by 150 lbs (68 kg) plus the rated
cargo load. SeeLoading the
Vehicle on page 4-35.
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 vehicle’s
capacity weight and the
original equipment tire size
and recommended ination
pressure. See “Tire and
Loading Information Label”
underLoading the Vehicle
on page 4-35.
5-50 Service and Appearance Care

Ination - Tire Pressure
Tires need the correct amount of
air pressure to operate effectively.
Notice:Do not let anyone tell
you that under-ination or
over-ination is all right. It is
not. If your tires do not have
enough air (under-ination),
you can get the following:
Too much exing
Too much heat
Tire overloading
Premature or irregular wear
Poor handling
Reduced fuel economy
If your tires have too much air
(over-ination), you can get
the following:
Unusual wear
Poor handling
Rough ride
Needless damage from road
hazardsA vehicle specic Tire and
Loading Information label is
attached to your vehicle.
This label shows your vehicle’s
original equipment tires and
the correct ination pressures for
your tires when they are cold.
The recommended cold tire
ination pressure, shown on the
label, is the minimum amount
of air pressure needed to
support your vehicle’s maximum
load carrying capacity.
For additional information
regarding how much weight your
vehicle can carry, and an
example of the Tire and Loading
Information label, seeLoading
the Vehicle on page 4-35.
How you load your vehicle
affects vehicle handling and ride
comfort. Never load your vehicle
with more weight than it was
designed to carry.When to Check
Check your tires once a month
or more. Also check the tire
pressure of the spare tire. If your
vehicle has a compact spare
tire, it should be at 60 psi
(420 kPa). SeeSpare Tire on
page 5-82for additional
information.
How to Check
Use a good quality pocket-type
gage to check tire pressure.
You cannot tell if your tires are
properly inated simply by
looking at them. Radial tires may
look properly inated even
when they are underinated.
Check the tire’s ination
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).
Service and Appearance Care 5-51

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 ination pressure
matches the recommended
pressure on the Tire and
Loading Information label, no
further adjustment is necessary.
If the ination pressure is low,
add air until you reach the
recommended amount.
If you overll 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 Pressure Monitor
System
The Tire Pressure Monitor System
(TPMS) uses radio and sensor
technology to check tire pressure
levels. The TPMS sensors monitor
the air pressure in your vehicle’s
tires and transmit tire pressure
readings to a receiver located in
the vehicle.
Each tire, including the spare
(if provided), should be checked
monthly when cold and inated to
the ination pressure recommended
by the vehicle manufacturer on
the vehicle placard or tire ination
pressure label. (If your vehicle
has tires of a different size than
the size indicated on the vehicle
placard or tire ination pressure
label, you should determine the
proper tire ination pressure
for those tires.)As an added safety feature, your
vehicle has been equipped with
a tire pressure monitoring system
(TPMS) that illuminates a low
tire pressure telltale when one or
more of your tires is signicantly
under-inated.
Accordingly, when the low tire
pressure telltale illuminates, you
should stop and check your tires as
soon as possible, and inate them
to the proper pressure. Driving on a
signicantly under-inated tire
causes the tire to overheat and can
lead to tire failure. Under-ination
also reduces fuel efficiency and tire
tread life, and may affect the
vehicle’s handling and stopping
ability.
Please note that the TPMS is
not a substitute for proper tire
maintenance, and it is the driver’s
responsibility to maintain correct tire
pressure, even if under-ination
has not reached the level to trigger
illumination of the TPMS low tire
pressure telltale.
5-52 Service and Appearance Care