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 shoulder and maximum section width.
Treadwear
The treadwear grade is a comparative rating based on the wear rate of the tire 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.
Uniform Tire Quality Grading
For example:
Treadwear 200
Traction AA
Temperature A
All passenger car tires must conform to Federal Safety Requirements in addition to these grades.
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.
Traction
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 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.
Temperature
Warning: The temperature grade fo r this ries established for a tire that is properly inflated and not overloaded. Excessive speed, underinflation, or excessive loading, either separately or in combination, can casue heat buildup and possible tire failure.
See also:
Automatic Transmission Fluid
Check the fluid level with the engine at normal operating temperature.
1. Park the vehicle on level ground.
Start the engine, let it run until the radiator fan comes on, then shut off the
engine ...
Automatic Transferring
If you get into the vehicle while you are on the phone, the call can be automatically
transferred to HFL.
1. Press the PHONE
button or the button.
2. Rotate to select Phone Setup,
then ...
Region Setting*
The audio system’s region setting will be lost when the battery is
disconnected or
goes dead.
If the Region Select screen appears, you need to set the region for the
audio
system. Follow th ...






