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.
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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.
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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 may depart significantly from the norm due to variations in
driving habits, service practices, and differences in road characteristics
and climate.
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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.
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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
excessive loading, either separately or in combination, can cause heat
buildup and possible tire failure.
Air Conditioning
U.S. Models
To ensure proper and safe operation, the Society of Automotive Engineers (SAE
J2845) recommends that the refrigerant system only be serviced by trained and
certified technicians.
Never repair or replace the air conditioning
evaporator (cooling coil) with one removed
from a used or salvaged vehicle.
New replacement mobile air conditioning
evaporators must be certified (and labeled)
as meeting SAE Standard J2842.
Vented refrigerant is harmful to the environment. To avoid refrigerant from
venting, never replace the evaporator with one removed from a used or
salvaged vehicle.
Refrigerant in your vehicle's air conditioning system is flammable and can be
ignited during servicing if proper procedures are not followed.
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