
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 5-64.
Your vehicle’s original equipment tires are listed on the
Tire and Loading Information Label. SeeLoading
the Vehicle on page 4-34, 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 speci c wheel and tire
systems developed for your vehicle, and have
them properly installed by a GM certi ed
technician.
SeeBuying New Tires on page 5-71andAccessories
and Modi cations on page 5-3for additional information.
5-73

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.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.
Treadwear
The treadwear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a speci ed
government test course. For example, a tire
graded 150 would wear one and a half (1.5) 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 signi cantly from
the norm due to variations in driving habits, service
practices, and differences in road characteristics
and climate.
5-74

Tire Chains
{CAUTION:
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.
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 nd traction devices that will t, 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.
5-78

To store the tools, follow these steps:
1. Return the tools to the tool bag and place it back in
the top-box storage unit.
2. Assemble the wheel blocks and jack together with
the wing nut by reversing Step 2 underRemoving
the Spare Tire and Tools on page 5-81
3. Replace the jack cover and tighten the jack-cover
wing nuts.
Spare Tire
Your vehicle, when new, had a fully-in ated spare tire.
A spare tire may lose air over time, so check its
in ation pressure regularly. SeeIn ation - Tire Pressure
on page 5-63andLoading the Vehicle on page 4-34
for information regarding proper tire in ation and loading
your vehicle. For instruction on how to remove, install
or store a spare tire, seeRemoving the Flat Tire
and Installing the Spare Tire on page 5-86andStoring
a Flat or Spare Tire and Tools on page 5-95.
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 at 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 in ated. Have the damaged or at 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 t. 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.
5-99