tire size GMC YUKON XL 2010 User Guide

Light Truck (LT‐Metric) Tire
(A) Light Truck (LT‐Metric) Tire:The United
States version of a metric tire sizing system.
The letters LT as the first 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.
(F) Load Range
:Load Range.
(G) Service Description
:The service description
indicates the load index and speed rating of a tire.
If two numbers are given as in the example,
120/116, then this represents the load index for
single versus dual wheel usage (single/dual).
The speed rating is the maximum speed a tire
is certified to carry a load.
6-68

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. See When It Is Time for New Tires
on
page 6‑79
. 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 6‑82.
Vehicle Capacity Weight
:The number of
designated seating positions multiplied by 150 lbs
(68 kg) plus the rated cargo load. See Loading the
Vehicle
on page 5‑31.
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 inflation pressure. See “Tire and
Loading Information Label” underLoading the
Vehicle
on page 5‑31.
6-71

How to Check
Use a good quality pocket-type gauge to check
tire pressure. You cannot tell if your tires are
properly inflated simply by looking at them.
Radial tires may look properly inflated even
when they are underinflated. Check the tire's
inflation 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 gauge firmly onto the valve to get
a pressure measurement. If the cold tire inflation
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 overfill the tire, release air by pushing on
the metal stem in the center of the tire valve.
Recheck the tire pressure with the tire gauge.
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 inflated to the inflation
pressure recommended by the vehicle manufacturer
on the vehicle placard or tire inflation pressure label.
(If your vehicle has tires of a different size than the size
indicated on the vehicle placard or tire inflation pressure
label, you should determine the proper tire inflation
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 significantly under‐inflated.
6-73

Tire Pressure Monitor Operation
If your vehicle is a Two‐mode Hybrid, see the
Two‐mode Hybrid manual for more information.
This vehicle may have a Tire Pressure Monitor System
(TPMS). The TPMS is designed to warn the driver when
a low tire pressure condition exists. TPMS sensors are
mounted onto each tire and wheel assembly, excluding
the spare tire and wheel assembly. The TPMS sensors
monitor the air pressure in the vehicle's tires and
transmit the tire pressure readings to a receiver located
in the vehicle.
When a low tire pressure
condition is detected, the
TPMS illuminates the low
tire pressure warning light
located on the instrument
panel cluster.
At the same time a message to check the pressure in a
specific tire appears on the Driver Information Center
(DIC) display. The low tire pressure warning light and
the DIC warning message come on at each ignition
cycle until the tires are inflated to the correct inflation
pressure. Using the DIC, tire pressure levels can be viewed by the driver. For additional information and
details about the DIC operation and displays see
DIC
Operation and Displays (With DIC Buttons)
on
page 4‑48or DIC Operation and Displays (Without DIC
Buttons)on page 4‑55and DIC Warnings and
Messages on page 4‑61.
The low tire pressure warning light may come on in cool
weather when the vehicle is first started, and then turn
off as you start to drive. This could be an early indicator
that the air pressure in the tire(s) are getting low and
need to be inflated to the proper pressure.
A Tire and Loading Information label, attached to your
vehicle, shows the size of your vehicle's original
equipment tires and the correct inflation pressure for
your vehicle's tires when they are cold. See Loading the
Vehicle
on page 5‑31, for an example of the Tire and
Loading Information label and its location on your
vehicle. Also see Inflation - Tire Pressure on page 6‑72.
Your vehicle's TPMS can warn you about a low tire
pressure condition but it does not replace normal tire
maintenance. See Tire Inspection and Rotation
on
page 6‑78and Tires on page 6‑63.
Notice: Liquid tire sealants could damage the Tire
Pressure Monitor System (TPMS) sensors. Sensor
damage caused by using a tire sealant is not
covered by your warranty. Do not use liquid tire
sealants.
6-75

You need new tires 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.
The rubber in tires degrades over time, even if they are
not being used. This is also true for the spare tire,
if your vehicle has one. Multiple conditions affect how
fast this aging takes place, including temperatures,
loading conditions, and inflation pressure maintenance.
With proper care and maintenance tires will typically
wear out before they degrade due to age. If you are
unsure about the need to replace your tires as they get
older, consult the tire manufacturer for more information.
Buying New Tires
GM has developed and matched specific 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 Specification
(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 specifications 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 near the tire
size. If the tires have an all‐season tread design, the
TPC spec number will be followed by an MS for mud
and snow. See Tire Sidewall Labeling
on page 6‑64for additional information.
6-80

GM recommends replacing tires in sets of four. This is
because uniform tread depth on all tires will help keep
your vehicle performing most like it did when the tires
were new. Replacing less than a full set of tires can
affect the braking and handling performance of your
vehicle. SeeTire Inspection and Rotation
on page 6‑78for information on proper tire rotation.
{WARNING:
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
might not handle properly, and you could have
a crash. Using tires of different sizes, brands,
or types could 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.
{WARNING:
If you use bias-ply tires on the vehicle,
the wheel rim flanges 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
the 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. See Tire
Pressure Monitor System on page 6‑73.
Your vehicle's original equipment tires are listed on the
Tire and Loading Information Label. See Loading the
Vehicle
on page 5‑31, for more information about the
Tire and Loading Information Label and its location on
your vehicle.
6-81

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.
{WARNING:
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 specific wheel and tire
systems developed for your vehicle, and have
them properly installed by a GM certified
technician.
See Buying New Tires
on page 6‑80andAccessories
and Modificationson page 6‑4for additional
information.
Uniform Tire Quality Grading
Quality grades can be found where applicable
on the tire sidewall between tread shoulder and
maximum section width. For example:
Treadwear 200 Traction AA
Temperature A
The following information relates to the system
developed by the United States National
Highway Traffic Safety Administration (NHTSA),
which grades tires by treadwear, traction, and
temperature performance. This applies only to
vehicles sold in the United States. The grades are
molded on the sidewalls of most passenger car
tires. The Uniform Tire Quality Grading (UTQG)
system does not apply to deep tread, winter-type
snow tires, space-saver, or temporary use
spare tires, tires with nominal rim diameters
of 10 to 12 inches (25 to 30 cm), or to some
limited-production tires.
6-82

Used Replacement Wheels
{WARNING:
Putting a used wheel on the 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
If your vehicle is a Two‐mode Hybrid, see the
Two‐mode Hybrid manual for more information.
{WARNING:
If your vehicle has P265/65R18 or P275/55R20
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(Continued)
WARNING: (Continued)
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.
Use another type of traction device only if its
manufacturer recommends it for use on your
vehicle and tire size combination and road
conditions. Follow that manufacturer's
instructions. To help avoid damage to your
vehicle, drive slowly, readjust or remove the
device if it is contacting your vehicle, and do
not spin your vehicle's wheels.
If you do find traction devices that will fit, install
them on the rear tires.
6-86

Notice:If your vehicle has P265/70R17 size tires,
use tire chains only where legal and only when you
must. Use chains that are the proper size for your
vehicle's tires. Install them on the rear tires only.
Do not use chains on the front tires.
Tighten them as tightly as possible with the ends
securely fastened. Drive slowly and follow the chain
manufacturer's instructions. If you can hear the
chains contacting your vehicle, stop and retighten
them. If the contact continues, slow down until it
stops. Driving too fast or spinning the wheels with
chains on will damage your vehicle.
If a Tire Goes Flat
It is unusual for a tire to blowout while you are driving,
especially if you maintain your vehicle's tires properly.
If air goes out of a tire, it is much more likely to leak out
slowly. But if you should ever have a blowout, here are
a few tips about what to expect and what to do:
If a front tire fails, the flat tire creates a drag that pulls
the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel firmly.
Steer to maintain lane position, and then gently brake
to a stop well out of the traffic lane. A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you would
use in a skid. In any rear blowout remove your foot from
the accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle to go. It may be
very bumpy and noisy, but you can still steer. Gently
brake to a stop, well off the road if possible.
{WARNING:
Lifting a vehicle and getting under it to do
maintenance or repairs is dangerous without
the appropriate safety equipment and training.
If a jack is provided with the vehicle, it is designed
only for changing a flat tire. If it is used for
anything else, you or others could be badly
injured or killed if the vehicle slips off the jack.
If a jack is provided with the vehicle, only use it
for changing a flat tire.
If a tire goes flat, the next part shows how to use the
jacking equipment to change a flat tire safely.
6-87

Spare Tire
Your vehicle, when new, had a fully-inflated spare tire.
A spare tire may lose air over time, so check its inflation
pressure regularly. SeeInflation - Tire Pressure
on
page 6‑72and Loading the Vehicleon page 5‑31for
information regarding proper tire inflation and loading
your vehicle. For instruction on how to remove, install
or store a spare tire, see Removing the Flat Tire and
Installing the Spare Tire
on page 6‑94and Storing a
Flat or Spare Tire and Tools on page 6‑103.
Notice: If the vehicle has four-wheel drive and the
different size spare tire is installed on the vehicle,
do not drive in four-wheel drive until you can have
your flat tire repaired and/or replaced. You could
damage the vehicle, and the repair costs would not
be covered by your warranty. Never use four-wheel
drive when the different size spare tire is installed
on the vehicle. Your vehicle may have a different size spare tire than
the road tires originally installed on your vehicle. This
spare tire was developed for use on your vehicle, so it
is all right to drive on it. If your vehicle has four-wheel
drive and the different size spare tire is installed, keep
the vehicle in two-wheel drive.
After installing the spare tire on your vehicle, you should
stop as soon as possible and make sure the spare tire
is correctly inflated. Have the damaged or flat road tire
repaired or replaced as soon as you can and installed
back onto your vehicle. This way, the spare tire will be
available in case you need it again.
Do not mix tires and wheels of different sizes, because
they will not fit. Keep your spare tire and its wheel
together. If your vehicle has a spare tire that does not
match your vehicle's original road tires and wheels
in size and type, do not include the spare in the tire
rotation.
6-107