Understand Tire Ratings - Quick Guide
A good first step is to understand car tire ratings. With an understanding of the basic categories and meanings of tire ratings.
In the United States the tire ratings standards come from the Department of Transportation. The measurement system is called Uniform Tire Quality Grading(UTQG). This gives the overall grading system for tires and how they should perform against specific criteria laid out buy the US Government.
Tire Ratings - Traction grades
Traction grades are an indication of a tire's ability to stop on wet pavement. A higher graded tire should allow a car to stop on wet roads in a shorter distance than a tire with a lower grade. Traction is graded from highest to lowest as "AA", "A", "B", and "C".
Of current tires:
- 3% are rated “AA”
- 75% are rated “A”
- 22% are rated “B”
- only 1 line of tires rated “C”
Treadwear grades are an indication of a tire's relative wear rate. The higher the treadwear number is, the longer it should take for the tread to wear down.
A control tire is assigned a grade of 100. Other tires are compared to the control tire. For example, a tire grade of 200 should wear twice as long as the control tire.
Of current tires:
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15% are rated below 200
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25% are rated 201 - 300
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32% are rated 301 - 400
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20% are rated 401 - 500
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6% are rated 501 - 600
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2% are rated above 600
Temperature grades are an indication of a tire's resistance to heat. Sustained high temperature (for example, driving long distances in hot weather), can cause a tire to deteriorate, leading to blowouts and tread separation. From highest to lowest, a tire's resistance to heat is graded as “A”, “B”, or “C”.
Of current tires:
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27% are rated “A”
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59% are rated “B”
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11% are rated “C”

