FORD 2002 Explorer Sport Trac v.1 - Manual (Page 204)

INFORMATION ABOUT UNIFORM TIRE QUALITY GRADING
New vehicles are fitted with tires
that have a rating on them called
Tire Quality Grades. The 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
These Tire Quality Grades are determined by standards that the United
States Department of Transportation has set.
Tire Quality Grades apply to new pneumatic tires for use on passenger
cars. They do 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 or limited production tires as defined in
Title 49 Code of Federal Regulations Part 575.104(c)(2).
U.S. Department of Transportation-Tire quality grades: The U.S.
Department of Transportation requires Ford to give you the following
information about tire grades exactly as the government has written it.
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 one-half (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.
Traction AA A B C
The traction grades, from highest to lowest are AA, A, B, and C. The
grades 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.
Maintenance and care
204