Downloaded from www.Manualslib.com manuals search engine The following information relates to the system
developed by the United States National Highway
Traffic Safety Adrninistratiorl. 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
nonlinal rim diameters of
10 to I2 inches (25 to 30 cm j.
or to some limited-production tires.
While
the tires available on General Motors passenger
car,s and light trucks may vary with respect to these
requirements and additional General
Motors Tire
Performance Criteria
(TPC) standards.
* orades, they must also conform to Federal safety
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 1/2) times as well on the government course as a tire
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.
0 oraded 100. The relative performance of tires depends
The traction grades, from highest to
lowest, are A, B
and C, and they represent the tire’s ability to stop on
wet pavement
as measured under controlled conditions
on 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 (straightaheadj traction tests and does not
include cornering (turning) traction.
