DOT Tire Quality Grading (U.S. Vehicles)
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. The following explains these gradings.
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
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 onehalf (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.
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.
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 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 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.
See also:
Overheating
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Overheating symptoms are as follows:
• The temperature gauge needle is at
the mark or the engine suddenly
loses
power.
• Steam is coming out of the engine compart ...
Checking the Battery
Check the condition of the battery monthly by looking at the test indicator window.
The label on the battery explains the test indicator’s colors.
The location of the test indicator window vari ...
Climate Control System
Press the AUTO button to activate the climate control system.
Press the button to turn the system
on or off.
Press the button to defrost the
windshield.
Models with navigation system
The climat ...






