Uniform tire quality grading 83, Pg. 83 wheels and tires – Volvo S40 User Manual
Page 112
2003 Volvo S40 & V40
pg. 83 Wheels and tires
Uniform tire quality grading
ALL PASSENGER CAR TIRES MUST CONFORM TO FEDERAL SAFETY REQUIREMENTS
IN ADDITION TO THESE GRADES
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 many depart
significantly from the norm due to variation in driving habits, service practices and differences in road
characteristics and climate.
TRACTION
The traction grades, from highest to lowest, are AA, A, B, and C, as measured under controlled
conditions on specified 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
reflect cornering (turning) traction.
TEMPERATURE
The temperature grades are AA (the highest), A, 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 Safety
Standard No. 109. Grades B and A represent higher levels of performance on the laboratory test wheel
than the minimum required by law.
UNIFORM TIRE QUALITY GRADING
LOCATING THE GRADE
Quality grades can be found where applicable on the tire sidewall between tread shoulder and maximum
section width.
Treadware 200 Traction AA Temperature A
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