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 grade 150
would wear one and one-half
(1 1/2) times as well on the
government course as a tire grade
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 A B C
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 test surfaces of asphalt and
concrete. A tire marked C may
have poor traction performance.
Maintenance and care
150
The traction grade
assigned to this tire is
based on braking (straight
ahead) traction tests and does
not include cornering (turning)
traction.
Temperature A B C
The temperature grades are A (the
highest), B, and C, representing
the tire's resistance to the
generation of heat and its ability to
dissipate heat when tested under
controlled conditions on a
specified indoor laboratory test
wheel. Sustained high temperature
can cause the material of the tire
to degenerate and reduce tire life,
and excessive temperature can
lead to sudden tire failure. The
grade C corresponds to a level of
performance which all passenger
car tires must meet under the
Federal Motor Vehicle Safety
Standard No. 109. Grades B and A
represent higher levels of
performance on the laboratory test
wheel than the minimum required
by law.
The temperature grade for
this tire is established for a
tire that is properly inflated and
not overloaded. Excessive speed,
underinflation, or excessive
loading, either separately or in
combination, can cause heat
buildup and possible tire failure.
Maintenance and care
151
