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.
511
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.
CAUTION: (Continued)
CAUTION: (Continued)
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.
514
Towing
Recreational Vehicle................................. 408
Towing a Trailer....................................... 414
Your Vehicle............................................. 408
Traction
StabiliTrak
®System................................. 359
Trailer
Recommendations.................................... 428
Transmission
Fluid, Automatic....................................... 454
Transmission Operation, Automatic.............. 128
Trip Odometer............................................. 241
Truck-Camper Loading Information.............. 407
Turn and Lane-Change Signals................... 208
Turn Signal/Multifunction Lever.................... 207
U
Ultrasonic Rear Parking Assist (URPA)........ 222
Understanding Radio Reception................... 348
Uniform Tire Quality Grading....................... 511
Universal Home Remote System........159, 160
Operation........................................161, 166
V
Vehicle
Control..................................................... 356
Damage Warnings....................................... 5
Loading.................................................... 402
Symbols...................................................... 5
Vehicle Customization, DIC......................... 278
Vehicle Data Collection and Event
Data Recorders........................................ 594
Vehicle Identi cation
Number (VIN).......................................... 546
Service Parts Identi cation Label.............. 546
Ventilation Adjustment.................................. 238
Visors.......................................................... 118
Voltmeter Gage........................................... 246
617