739
Maintenance
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Uniform tire quality grading The following information relates to
the tire grading system developed by
the Canadian Motor Vehicle Safety
Standard (CMVSS) for grading tires
by tread wear, traction and tempera-
ture performance.
Tread wearThe tread wear grade is a compara-
tive rating based on the wear rate of
the tire when tested under controlled
conditions on a specified govern-
ment test course. For example, a tire
graded 150 would wear one-and-a-
half 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, performance
may differ from the norm because of
variations in driving habits, service
practices and differences in road
characteristics and climate.
These grades are molded on the
side-walls of passenger vehicle tires.
The tires available as standard or
optional equipment on Kia vehicles
may vary with respect to grade.
Traction - A, B & C The traction grades, from highest to
lowest, are A, B and C. The grades
represent the tires 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.Temperature -A, B & C The temperature grades are A (the
highest), B and C. The grades repre-
sent the tire’s resistance to the gener-
ation of heat and its ability to dissipate
heat when tested under controlled
conditions on a specified indoor labo-
ratory test wheel.
Sustained high temperature can
cause the material of the tires to
degenerate and reduce tires life, and
excessive temperature can lead to
sudden tires failure. Grades A and B
represent higher levels of perform-
ance on the laboratory test wheel
than the minimum required by the law.
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2GHA741
Tread wear XXX Traction X Temperature X
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