Quick Answer
UTQG stands for Uniform Tire Quality Grading (NHTSA, 49 CFR 575.104), with three grades molded on the tire sidewall. Treadwear is a comparison with a grade-100 reference tire on the government course: 500 should wear five times as well. Traction grades wet straight-ahead braking: AA (more than 0.54 on asphalt), A, B, C. Temperature grades heat resistance on a laboratory test wheel: A (completes the 575 rpm stage, about 115 mph), B, C.
Example: 500 A A = treadwear 500, traction A and temperature A. The regulation states no mileage. UTQG appears on the upper sidewall near the tread shoulder, formatted as: TREADWEAR 500 TRACTION A TEMPERATURE A
Interactive UTQG Decoder
Enter the three UTQG values printed on your tire's sidewall (e.g. 500 A A).
Number 60–1000
Wet braking grade
Heat resistance grade
What Common UTQG Codes Mean
Read a UTQG code in three parts: the number is treadwear, the first letter is traction, and the last letter is temperature. So 640 B A is treadwear 640, traction B, temperature A. Treadwear is a comparison with a reference tire, not a mileage promise: NHTSA says a tire graded 150 wears one and one-half times as well as a tire graded 100 on the government course.
| Code | Treadwear | Traction | Temperature |
|---|---|---|---|
| 500 A A | 5 times the wear life of the grade 100 reference tire on the government test course | A: more than 0.47 on asphalt and 0.35 on concrete | A: highest, passed the 575 rpm laboratory test wheel stage |
| 500 AA A | 5 times the wear life of the grade 100 reference tire on the government test course | AA: more than 0.54 on asphalt and 0.38 on concrete (the highest grade) | A: highest, passed the 575 rpm laboratory test wheel stage |
| 540 AA A | 5.4 times the wear life of the grade 100 reference tire on the government test course | AA: more than 0.54 on asphalt and 0.38 on concrete (the highest grade) | A: highest, passed the 575 rpm laboratory test wheel stage |
| 600 A B | 6 times the wear life of the grade 100 reference tire on the government test course | A: more than 0.47 on asphalt and 0.35 on concrete | B: passed the 500 rpm stage but not the 575 rpm stage |
| 640 B A | 6.4 times the wear life of the grade 100 reference tire on the government test course | B: more than 0.38 on asphalt and 0.26 on concrete | A: highest, passed the 575 rpm laboratory test wheel stage |
| 700 A A | 7 times the wear life of the grade 100 reference tire on the government test course | A: more than 0.47 on asphalt and 0.35 on concrete | A: highest, passed the 575 rpm laboratory test wheel stage |
| 800 AA A | 8 times the wear life of the grade 100 reference tire on the government test course | AA: more than 0.54 on asphalt and 0.38 on concrete (the highest grade) | A: highest, passed the 575 rpm laboratory test wheel stage |
| 820 A B | 8.2 times the wear life of the grade 100 reference tire on the government test course | A: more than 0.47 on asphalt and 0.35 on concrete | B: passed the 500 rpm stage but not the 575 rpm stage |
Source: NHTSA, 49 CFR 575.104, Uniform Tire Quality Grading Standards. Traction grades are straight-ahead wet braking results only. A temperature grade of C corresponds to the level all passenger car tires must meet under FMVSS No. 109; grades B and A represent higher levels of performance on the laboratory test wheel.
Each grade has its own page: the treadwear grade and tread depth explainer covers the number, and the temperature grade chart for A, B and C covers the last letter.
Component 1: Treadwear Rating
The treadwear rating is the most popular and most misunderstood component of UTQG. It is a relative index: not a direct mileage prediction.
The government test course is a roughly 400-mile loop near San Angelo, Texas. A convoy runs two circuits (800 miles) of break-in and then 16 circuits (about 6,400 miles). Tread depth is measured, wear rate is projected and corrected using course monitoring tires run in the same convoy, and the grade is the tire's result as a percentage of the NHTSA nominal treadwear value, rounded down to a multiple of 20.
Example: a tire graded 150 should wear one and one-half times as well on the government course as a tire graded 100.
| Treadwear Grade | Relative to the Reference Tire | Share of Current Tire Lines (NHTSA) |
|---|---|---|
| Below 200 | Under 2× the grade-100 reference tire | 15% |
| 201–300 | 2× to 3× | 25% |
| 301–400 | 3× to 4× | 32% |
| 401–500 | 4× to 5× | 20% |
| 501–600 | 5× to 6× | 6% |
| Above 600 | Over 6× | 2% |
Treadwear Is Not a Mileage
Tire manufacturers and brand name owners assign the grades, and the regulation requires each tire to be able to achieve the level of performance it is labeled with. NHTSA says the relative performance of tires depends on actual conditions of use and may depart significantly from the norm because of driving habits, service practices, and differences in road characteristics and climate.
Component 2: Traction Grade
The traction grade measures wet straight-ahead braking: a locked-wheel test at 40 mph on wet asphalt and wet concrete skid pads, with the result adjusted against a standard tire.
| Grade | Asphalt Coefficient | Concrete Coefficient | Share of Current Tire Lines (NHTSA) |
|---|---|---|---|
| AA | More than 0.54 | More than 0.38 | 15% |
| A | More than 0.47 | More than 0.35 | 77% |
| B | More than 0.38 | More than 0.26 | 7% |
| C | 0.38 or less | 0.26 or less (either surface puts a tire in C) | Only 4 tire lines |
- Acceleration
- Cornering
- Hydroplaning
- Peak traction
NHTSA's warning on the grade says it is based on straight-ahead braking tests and does not include acceleration, cornering, hydroplaning or peak traction characteristics.
Component 3: Temperature Grade
The temperature grade represents the tire's resistance to the generation of heat and its ability to dissipate heat, tested on an indoor laboratory test wheel at 95 °F.
| Grade | Test Result Required | Note |
|---|---|---|
| A | Completes the 575 rpm stage (about 115 mph on the test wheel) | Share of current tire lines: 62% |
| B | Completes the 500 rpm stage (about 100 mph) but not the 575 rpm stage | Share of current tire lines: 34% |
| C | Does not complete the 500 rpm stage | Share of current tire lines: 4%. Grade C corresponds to the level all passenger car tires must meet under FMVSS No. 109. |
NHTSA explains that sustained high temperature can cause the material of the tire to degenerate and reduce tire life, and that excessive temperature can lead to sudden tire failure. The grade is established for a tire that is properly inflated and not overloaded; excessive speed, underinflation or excessive loading, separately or together, can cause heat buildup and possible tire failure.
How to Use UTQG When Buying Tires
Start with the size your vehicle specifies
Check your owner's manual or the Tire and Loading Information label for the right size (NHTSA). UTQG grades only compare tires of the passenger car type that carry them.
Read all three grades on the sidewall
Look between the tread shoulder and the maximum section width, for example Treadwear 200 Traction AA Temperature A. Compare each grade separately; they measure different things.
Treat traction as straight-ahead wet braking only
NHTSA's warning on the grade explains that it is based on straight-ahead braking tests and does not include acceleration, cornering, hydroplaning or peak traction.
Treat treadwear as a comparison, not a mileage
A tire graded 150 should wear one and one-half times as well on the government course as a tire graded 100. NHTSA says real-world performance depends on driving habits, service practices, road characteristics and climate and may differ significantly.
Frequently Asked Questions
What does UTQG mean on a tire?
UTQG stands for Uniform Tire Quality Grading, set out in NHTSA's 49 CFR 575.104. It has three grades molded on the sidewall between the tread shoulder and the maximum section width. Treadwear is a comparative rating based on the wear rate of the tire on the government test course: a tire graded 150 should wear one and one-half times as well as a tire graded 100. Traction (AA, A, B, C) grades wet straight-ahead braking on asphalt and concrete. Temperature (A, B, C) grades resistance to heat generation and ability to dissipate heat on a laboratory test wheel.
What is a good UTQG treadwear rating?
There is no official "good" number. Treadwear is a comparison: a higher number should take longer to wear down on the government course. NHTSA publishes the spread for current tire lines: 15% are rated below 200, 25% are 201 to 300, 32% are 301 to 400, 20% are 401 to 500, 6% are 501 to 600 and 2% are above 600. NHTSA also says real-world performance may depart significantly from the norm because of driving habits, service practices, road characteristics and climate.
What does treadwear 500 mean on a tire?
Treadwear 500 means the tire is graded at 500% of the NHTSA nominal treadwear value, so it should wear five times as well as a tire graded 100 on the government test course (a roughly 400-mile loop near San Angelo, Texas, run for 16 circuits after an 800-mile break-in). The regulation states no mileage, and we do not give one.
What does traction grade AA mean on a tire?
AA is the highest traction grade. To be graded AA a tire needs an adjusted wet locked-wheel traction coefficient of more than 0.54 on the asphalt test surface and more than 0.38 on the concrete test surface, measured in straight-ahead braking at 40 mph. NHTSA warns that the grade does not include acceleration, cornering, hydroplaning or peak traction.
What is temperature grade A on a tire?
Temperature grade A is the highest. A tire may be graded A only if it completes the 575 rpm stage of the laboratory test: the tire is pressed against a 67.23-inch steel test wheel at 88% of its maximum load rating, run at 250 rpm for 2 hours and then stepped up from 375 rpm in 25 rpm increments of 30 minutes each to 575 rpm. At that wheel size 575 rpm is about 115 mph. B means it completes the 500 rpm stage (about 100 mph) but not 575, and C means it does not complete 500. NHTSA adds that excessive speed, underinflation or overloading can cause heat buildup and possible tire failure.
Do all tires have UTQG grades?
No. 49 CFR 575.104 applies to new pneumatic tires for passenger cars and does not apply to deep tread tires, winter-type snow tires, space-saver or temporary use spare tires, tires with nominal rim diameters of 12 inches or less, or limited production tires. A tire without UTQG markings may simply be in an exempt category.
Can I use UTQG to predict exactly how many miles my tires will last?
No. NHTSA describes treadwear as a comparative rating and says the relative performance of tires depends on actual conditions of use and may depart significantly from the norm because of driving habits, service practices, and differences in road characteristics and climate. Use it to compare tires, not to estimate mileage.
What is the NHTSA rating of tires on the road today?
NHTSA reports, for current tires: traction 15% AA, 77% A, 7% B and only 4 tire lines C; temperature 62% A, 34% B and 4% C. Treadwear is spread from below 200 to above 600, with the largest share (32%) between 301 and 400.
Who assigns UTQG grades?
Tire manufacturers and brand name owners provide the grades for their tires. The regulation requires that each tire be able to achieve the level of performance represented by each grade it is labeled with, and gives the test procedures in paragraphs (e), (f) and (g). NHTSA runs the government test course and skid pads.
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Disclaimer: UTQG grades are assigned by tire manufacturers following US NHTSA procedures and are intended for comparison under controlled test conditions. They do not guarantee a specific mileage or performance level for any individual driver, vehicle, or climate. Sources: 49 CFR 575.104 and NHTSA's TireWise page. Always consider UTQG together with your owner's manual and professional advice when selecting tires.