Automobile Repair/Tire
Tire is also important for the car system. If without those tires, the automobile itself won't be moving anywhere soon . Also , when buying tires, please make sure you are buying the best as these tires contact to ground on an area possibly equivalent or less than the size of postage stamp.
Before you buy tires, you may refer to these documents by US D.O.T and also search for the tires sold with the rating by US NHTSA : https://www.nhtsa.gov/ratings
Tires are graded as followed:
TREADWEAR GRADE
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 and 1/2) times as well on the government course as a tire graded 100. (The higher, the better it is for the user to have longer lasting tires on the road). 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 GRADE
The traction grades, from highest to lowest, are AA A, B, 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 performance. Warning: The traction grade assign to this may have poor traction- tire is based on braking (straight ahead) traction and does not include cornering (turns traction.)
| Traction Grade | Expected Performance on Wet Pavement |
|---|---|
| AA | Excellent traction and stopping ability |
| A | Good traction and stopping ability |
| B | Moderate traction and stopping ability |
| C | Poor traction and stopping ability |
TEMPERATURE GRADE:
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 then 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, under inflation, or excessive loading, either separately or in combination, can cause heat buildup and possible tire failure.