Changing Wheels - Volvo 2003 XC90 Manual

2003 VOLVO XC90
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, maintenance 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 is not a
measure of 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 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 minimum level of performance that all passenger vehicle 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.
WARNING!
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.
pg. 119 Wheels and tires

Changing wheels

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