2007 GMC SIERRA tire size

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.
(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.
Passenger (P-Metric) Tire
Light Truck (LT-Metric) Tire
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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 568.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 571.
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 425.
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
Your Vehicle on page 425.
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Tire Pressure Monitor System
The Tire Pressure Monitor System (TPMS) uses
radio and sensor technology to check tire pressure
levels. If your vehicle has this feature, sensors
are mounted on each tire and wheel assembly,
except the spare tire. The TPMS sensors monitor
the air pressure in your vehicle’s tires and
transmit tire pressure readings to a receiver
located in the vehicle.
The TPMS is designed to alert the driver, if a low
tire pressure condition exists. If your vehicle has the
Driver Information Center (DIC), the driver may also
check tire pressure levels using the DIC.
When a low tire pressure condition is detected,
the TPMS will illuminate the low tire pressure
warning symbol located on the instrument panel
cluster. If your vehicle has the DIC feature, a
message to check the pressure in a specic tire
will also appear on the DIC display. The low
tire pressure warning symbol on the instrument
panel cluster and the CHECK TIRE PRESSURE
warning message on the DIC display will appear at
each ignition cycle until the tires are inated to
the correct ination pressure.For additional information and details about the
DIC operation and displays seeDIC Operation and
Displays (With DIC Buttons) on page 268orDIC
Operation and Displays (Without DIC Buttons)
on page 275andDIC Warnings and Messages on
page 279.
You may notice, during cooler weather conditions,
that the tire pressure monitor light, located on
the instrument panel cluster, and the CHECK TIRE
PRESSURE message will appear when the
vehicle is rst started and then turn off as you
start to drive the vehicle. This could be an early
indicator that the tire pressures are getting low and
need to be inated to the proper pressure.
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.)
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The Tire and Loading Information label (tire
information placard) shows the size of your
vehicle’s original tires and the correct ination
pressure for your vehicle’s tires when they
are cold. SeeInation - Tire Pressure on
page 559. For the location of the tire and loading
information label, seeLoading Your Vehicle
on page 425.
Your vehicle’s TPMS can alert you about a low
tire pressure condition but it does not replace
normal tire maintenance. SeeTire Inspection and
Rotation on page 565andTires on page 550.
Notice:Do not use a tire sealant if your
vehicle has Tire Pressure Monitors. The liquid
sealant can damage the tire pressure monitor
sensors.
Resetting the TPMS Identication Codes
Each TPMS sensor has a unique identication
code. Any time you rotate your vehicle’s tires or
replace one or more of the TPMS sensors,
the identication codes will need to be matched to
the new tire/wheel position. The sensors arematched to the tire/wheel positions in the following
order: driver’s side front tire, passengers side
front tire, passengers side rear tire, and driver’s
side rear tire using a TPMS diagnostic tool.
See your GM dealer for service.
The TPMS sensors may also be matched to each
tire/wheel position by increasing or decreasing
the tire’s air pressure. If increasing the tire’s
air pressure, do not exceed the maximum ination
pressure indicated on the tire’s sidewall.
You will have two minutes to match the rst
tire/wheel position, and ve minutes overall to
match all four tire/wheel positions. If it takes longer
than two minutes, to match the rst tire and
wheel, or more than ve minutes to match all four
tire and wheel positions the matching process
stops and you will need to start over.
The TPMS sensor matching process is
outlined below:
1. Set the parking brake.
2. Turn the ignition switch to RUN with the
engine off.
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When It Is Time for New Tires
One way to tell when it
is 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. Some
commercial truck tires
may not have treadwear
indicators.
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 cannot be repaired well because of the
size or location of the damage.
Buying New Tires
GM has developed and matched specic tires for
your vehicle. The original equipment tires
installed on your vehicle, when it was new, were
designed to meet General Motors Tire
Performance Criteria Specication (TPC spec)
system rating. If you need replacement tires, GM
strongly recommends that you get tires with
the same TPC Spec rating. This way, your vehicle
will continue to have tires that are designed to
give the same performance and vehicle safety,
during normal use, as the original tires.
GM’s exclusive TPC Spec system considers over
a dozen critical specications that impact the
overall performance of your vehicle, including
brake system performance, ride and handling,
traction control, and tire pressure monitoring
performance. GM’s TPC Spec number is molded
onto the tire’s sidewall by the tire manufacturer.
If the tires have an all-season tread design,
the TPC spec number will be followed by an MS
for mud and snow. SeeTire Sidewall Labeling
on page 551for additional information.
568

{CAUTION:
Mixing tires could cause you to lose
control while driving. If you mix tires of
different sizes, brands, or types (radial
and bias-belted tires), the vehicle may not
handle properly, and you could have a
crash. Using tires of different sizes,
brands or types may also cause damage
to your vehicle. Be sure to use the same
size, brand, and type tires on all wheels.
Your vehicle may have a different size
spare than the road tires (those originally
installed on your vehicle). When new, your
vehicle included a spare tire and wheel
assembly with a similar overall diameter
as your vehicle’s road tires and wheels,
so it is all right to drive on it. Because
this spare was developed for use on your
vehicle, it will not affect vehicle handling.
{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.
If you must replace your vehicle’s tires with those
that do not have a TPC Spec number, make
sure they are the same size, load range, speed
rating, and construction type (radial and
bias-belted tires) as your vehicle’s original tires.
Vehicles that have a tire pressure monitoring
system may give an inaccurate low-pressure
warning if non-TPC spec rated tires are installed
on your vehicle. Non-TPC Spec rated tires
may give a low-pressure warning that is higher or
lower than the proper warning level you would
get with TPC Spec rated tires. SeeTire Pressure
Monitor System on page 561.
569

Your vehicle’s original equipment tires are listed
on the Tire and Loading Information Label.
This label is attached to the vehicle’s center pillar
(B-pillar). SeeLoading Your Vehicle on page 425,
for more information about the Tire and Loading
Information Label and its location on your vehicle.
Different Size Tires and Wheels
If you add wheels or tires that are a different size
than your original equipment wheels and tires,
this could affect the way your vehicle performs,
including its braking, ride and handling
characteristics, stability, and resistance to rollover.
Additionally, if your vehicle has electronic
systems such as anti-lock brakes, rollover airbags,
traction control, and electronic stability control,
the performance of these systems can be affected.
{CAUTION:
If you add different sized wheels, your
vehicle may not provide an acceptable
level of performance and safety if tires not
recommended for those wheels are
selected. You may increase the chance
that you will crash and suffer serious
injury. Only use GM specic wheel and
tire systems developed for your vehicle,
and have them properly installed by a GM
certied technician.
SeeBuying New Tires on page 568and
Accessories and Modications on page 486for
additional information.
570

Whenever a wheel, wheel bolt or wheel nut is
replaced on a dual wheel setup, check the wheel
nut torque after 100, 1,000 and 6,000 miles
(160, 1 600 and 10 000 km) of driving. For proper
torque, see “Wheel Nut Torque” underCapacities
and Specications on page 616.
SeeChanging a Flat Tire on page 576for more
information.
Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You cannot know how it has
been used or how far it has been driven. It
could fail suddenly and cause a crash. If
you have to replace a wheel, use a new
GM original equipment wheel.
Tire Chains
{CAUTION:
If your vehicle has dual wheels or
P265/65R18, P275/55R20 or LT265/70R17
size tires, do not use tire chains. They can
damage your vehicle because there is not
enough clearance. Tire chains used on a
vehicle without the proper amount of
clearance can cause damage to the
brakes, suspension, or other vehicle
parts. The area damaged by the tire
chains could cause you to lose control of
your vehicle and you or others may be
injured in a crash.
CAUTION: (Continued)
574