Uniform Tire Quality Grading
The following information relates to the system developed by the United States National Highway
Traffic Safety Administration, 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 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),
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 1
(1 1/2) 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.
I.
or to some limited-production tires. ;,*?;;x.,< .
. .'-I '.'Traction -- A, B, C
While the tires available on General Motors passenger 1
cars and light trucks may vary with respect to these The traction grades, from highest to lowest, are A, B, and
grades,, they must also conform to Federal safety
C, and they represent the tire's' ability to stop on wet
requirements and additional General Motors Tire pavement as measured under controlled conditioa
on
Peiformance Criteria (TPC) standards. 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 braking (straightahead) traction tests and does not
include cornering (turning) traction.
6-53
ProCarManuals.com
Trailer Brakes
..................................... 4-34
Driving on Grades
............................ 4-36
Hitches ..................................... 4-33
ParkingonHills
. ............................. 4-37
Safety Chains
.............. ................. 4-34
. Driving With ................................ 4-34
Maintenance When Towing
..................... 4-37
Tongueweight
............................... 4-32
Total Weight on Tires
.......................... 4-33
Weight
..................................... 4-32
Transmitters, Remote Lock Control
.................. 2-4
Transportation, Courtesy
.......................... 8-7
Trip Calculator
................................. 2-57
Trip Odometer
................................. 2-45
Access Panel
................................ 2-39
Release, Remote
............................... 2-7
Turn Signal and Lane Change Signals
............... 2-27
Turn Signal On
Chime ........................... 2-27
Turn SignalMultifunction Lever
................... 2-26
Turn Signals When Towing a Trailer
................ 4-36
Towing
..................................... 4-30
Turnsignals
................................. 4-36
Tr~nk
......................................... 2-7
Lock
........................................ 2-7
TTYUsers
..................................... 8-4
Underbody Flushing Service
..................... 7-39
Underbody Maintenance
......................... 6-62
Underhood Electrical Center ................. 6-68, 6-70
Vehicle
Control
...................................... 4-5
Damage Warnings .............................. iv Dimensions
........................ ... 6-75
Identification Number ......................... 6-64
Loading .................................... 4-28
Storage
..................................... 6-30
Ventilation System
............................... 3-3
Visor Vanity Mirrors ............................ 2-41
Visors, Sun
.................................... 2-41
Warning Lights, Gages and Indicators
............... 2-46
Washer Fluid, Windshield
........................ 6-25
Weatherstrips
................... .......... 6-60
warning
Devices
................................ 5-2
Washing Your Vehicle
.......... ............ 6-60
Wheel Alignment
.................................. 6-54
NutTorque
.................................. 5-30
Wrench
..................................... 5-25
Windows
..................................... 2-25
Auto-Down
................................. 2-25
LockOut
................................... 2-25
Power
...................................... 2-25
Windshield Washer
............................. 2-28
Fluid
.................................. 2-28. 6-25
Fluid Level Check ............................ 7-36
Windshield Wiper
.............................. 2-28
Blade Replacement
........................... 6-48
Winter Driving
................................. 4-24
WreckerTowing
................................. 5-7
Replacement
................................. 6-54
Fuses ...................................... 6-65
Wiring, Headlamp .............................. 6-65
Wrench. Wheel
................ ............ 5-25
9-10
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