9-1 . Specifications
563 and / or prospective purchasers of SUBARU vehicles with information on uniform tire quality grading .
Your SUBARU dealer will help answer any questions you may have as you read this information .
■ DOT quality grades
All passenger vehicle tires must conform to Federal Safety Requirements in addition to these grades . Quality grades can be found where applicable on the tire sidewall between tread shoulder and maximum section width .
For example : Treadwear 200 Traction AA Temperature A
■ 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 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 conditions of their use . Performance may differ 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 , and they 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 .
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 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 .
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 .
Warning : The temperature grades of a tire assume that it is properly inflated and not overloaded .
Excessive speed , underinflation , or
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Vehicle specifications