Toyota Echo 2001 User Manual page 213

Treadwear—The treadwear grade
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 graded 100. The relative performance
of tires depends upon the actual condi-
tions of their use, however, and may de-
part significantly from the norm due to
variations in driving habits, service prac-
tices and differences in road characteris-
tics and climate.
2001MY ECHO (U) L/O0008
is a Traction AA, A, B,
grades, from highest to lowest, are AA, A,
B, and C, and they represent the tire's
ability to stop on wet pavement as mea-
sured under controlled conditions on spe-
cified 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 (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 dissi-
pate heat when tested under controlled
conditions on a specified indoor laboratory
test wheel. Sustained high temperature
can cause the material of the tire to de-
generate and reduce tire life, and exces-
sive temperature can lead to sudden tire
failure. The grade C corresponds to a lev-
el 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 perfor-
mance on the laboratory test wheel than
the minimum required by law.
2001 ECHO (OM52440U)
C—The traction Warning: The temperature grades for this
tire are established for a tire that is prop-
erly inflated and not overloaded. Exces-
sive speed, underinflation, or excessive
loading, either separately or in combina-
tion, can cause heat buildup and possible
tire failure.
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