Black plate (53,1)GMC Yukon/Yukon XL Owner Manual - 2011
Vehicle Care 10-53
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.
Tire Terminology and
Definitions
Air Pressure:The amount
of air inside the tire pressing
outward on each square inch
of the tire. Air pressure is
expressed in psi (pounds per
square inch) or kPa (kilopascal).
Accessory Weight
: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.
Black plate (57,1)GMC Yukon/Yukon XL Owner Manual - 2011
Vehicle Care 10-57
A vehicle specific Tire and
Loading Information label is
attached to your vehicle. This
label shows your vehicle's
original equipment tires and the
correct inflation pressures for
your tires when they are cold.
The recommended cold tire
inflation 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, seeVehicle
Load Limits on page 9‑23. 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.
Do not forget to check the
pressure of the spare tire.
See
Full-Size Spare Tire on
page 10‑87 for additional
information.
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 1.6 km (1 mile). 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.
Black plate (65,1)GMC Yukon/Yukon XL Owner Manual - 2011
Vehicle Care 10-65
{WARNING
Tires could explode during
improper service. Attempting to
mount or dismount a tire could
cause injury or death. Only your
dealer or authorized tire service
center should mount or dismount
the tires.
{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 the vehicle. Be sure
to use the same size, brand, and
type of tires on all wheels.(Continued)
WARNING (Continued)
This vehicle may have a different
size spare than the road tires
(those originally installed on the
vehicle). When new, the vehicle
included a spare tire and wheel
assembly with a similar overall
diameter as the vehicle's road
tires and wheels, so it is all right
to drive on it. Because this spare
was developed for use on the
vehicle, it will not affect vehicle
handling.
{WARNING
Using bias-ply tires on the
vehicle may cause the wheel
rim flanges to develop cracks
after many miles of driving.
A tire and/or wheel could fail
(Continued)
WARNING (Continued)
suddenly and cause a crash.
Use only radial-ply tires with
the wheels on the vehicle.
If you must replace the 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 the
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 the 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 10‑58.
Black plate (67,1)GMC Yukon/Yukon XL Owner Manual - 2011
Vehicle Care 10-67
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.
While the tires available on
General Motors passenger cars
and light trucks may vary with
respect to these grades, they
must also conform to federal
safety requirements and
additional General Motors Tire
Performance Criteria (TPC)
standards.
All Passenger Car Tires Must
Conform to Federal Safety
Requirements In Addition To
These Grades.Treadwear
The treadwear grade is a
comparative rating based on the
wear rate of the tire when tested
under controlled conditions on
a specified government test
course. For example, a tire
graded 150 would wear one and
a half (1½) times as well on the
government course as a tire
graded 100. The relative
performance of tires depends
upon the actual conditions of
their use, however, and may
depart significantly from the
norm due to variations in
driving habits, service practices
and differences in road
characteristics and climate.
Traction
–AA, A, B, C
The traction grades, from
highest to lowest, are AA, A, B,
and C. Those grades represent
the tire's ability to stop on wet
pavement as measured under
controlled conditions on
specified government test
surfaces of asphalt and
concrete. A tire marked C may
have poor traction performance.
Warning: The traction grade
assigned to this tire is based on
straight-ahead braking traction
tests, and does not include
acceleration, cornering,
hydroplaning, or peak traction
characteristics.
Black plate (70,1)GMC Yukon/Yukon XL Owner Manual - 2011
10-70 Vehicle Care
Tire Chains
If your vehicle is a Hybrid, see
the Hybrid Supplement 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 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.(Continued)
WARNING (Continued)
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. 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.
Black plate (87,1)GMC Yukon/Yukon XL Owner Manual - 2011
Vehicle Care 10-87
Full-Size 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. See
Tire Pressure on page 10‑56and
Vehicle Load Limits on page 9‑23
for 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” and“Storing a
Flat or Spare Tire and Tools” under
Tire Changing on page 10‑72. 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.