GMC 2009 Sierra - Manual (Page 388)

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 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 5-74 and Accessories
and Modifications on page 5-3 for 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.
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.
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