FORD 2003 E-550 v.2 - Manual (Page 205)

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.
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.
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.
2003 Econoline (eco)
Owners Guide (post-2002-fmt)
USA English (fus)
Maintenance and Specifications
205