Dot Tire Quality Grading - Acura NSX Owner's Manual

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DOT Tire Quality Grading

The tires on your vehicle meet all U.S. Federal Safety Requirements. All tires are also
graded for treadwear, traction, and temperature performance according to
Department of Transportation (DOT) standards. These gradings are explained
below.
n Uniform Tire Quality Grading
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
All passenger car tires must conform to Federal Safety Requirements in addition
to these grades.
Treadwear
n
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 may depart
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significantly from the norm due to variations in driving habits, service practices,
and differences in road characteristics and climate.
n Traction
The traction grades, from highest to lowest, are AA, A, B, and C. Those grades
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 straight-ahead
braking traction tests, and does not include acceleration, cornering,
hydroplaning, or peak traction characteristics.
n Temperature
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. The
grade C corresponds to a level of performance which all passenger car tire 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 grade for this tire is established for a tire that is
properly inflated and not overloaded. Excessive speed, underinflation, or
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