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.
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 speci ed
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.
298
5. Plug the air compressor accessory plug (C)
into an accessory power outlet in the vehicle.
SeeAccessory Power Outlet(s) on page 121
for more information.
{CAUTION:
Idling the engine in a closed-in place or
with the climate control system off can
cause deadly carbon monoxide (CO).
SeeEngine Exhaust on page 91.
6. Start the vehicle. SeeStarting the Engine
on page 80for more information. The
vehicle must be running while using the
air compressor.
{CAUTION:
In ating something too much can make
it explode, and you or others could be
injured. Be sure to read the in ator
instructions, and in ate the tire to its
recommended pressure. Do not exceed
36 psi (248 kPa).
7. Move the in ator kit switch to the I (on) position.
The in ator kit forces sealant and air into the
tire. Sealant might leak from the puncture
hole until the vehicle is driven and the hole
has sealed.
8. Make sure there is a proper connection
between the tire valve stem and the
sealant lling hose by looking at the air
pressure gage. If there is not a pressure
reading while the compressor is running,
the connection between the in ator kit and
the tire is bad.
Check the attachment between the sealant
lling hose and the tire valve stem.
307