UTQG treadwear, traction and temperature markings
What the UTQG traction grade (AA, A, B, C) means, how it is tested, what it ignores, such as snow, and how to read treadwear and temperature grades.
Contents
The UTQG traction grade on a tire sidewall is AA, A, B or C. It shows how well the tire stopped in a straight line on wet pavement in a standardized US government test. AA is the highest grade and C is the lowest. The grade does not cover dry grip, cornering, resistance to hydroplaning, or performance on snow and ice. Traction is one of three Uniform Tire Quality Grading (UTQG) marks. The other two are a treadwear number and a temperature letter. All three are comparative test results. None of them is a safety rating or a mileage promise.
What UTQG is and where to find it
Uniform Tire Quality Grading is a US federal labeling requirement administered by the National Highway Traffic Safety Administration (NHTSA). It is defined in federal regulation 49 CFR 575.104. It applies to most passenger car tires sold in the US. Some tire types are exempt, including dedicated winter tires, temporary spare tires and light truck (LT) tires. A missing UTQG marking on those tires is normal. On graded tires, the marking is molded into the sidewall and usually reads like this:
TREADWEAR 500 TRACTION AA TEMPERATURE AHow the traction grade is tested
The test tire is mounted on an instrumented trailer and towed at 40 mph over wetted asphalt and wetted concrete test surfaces. The trailer's brakes then lock the test wheel, and the equipment measures the sliding friction between the tire and the road surface. The tire's grade depends on its results on both surfaces. To earn a grade, a tire must exceed that grade's threshold on asphalt and on concrete.
| Traction grade | Wet asphalt friction coefficient | Wet concrete friction coefficient |
| AA | above 0.54 | above 0.38 |
| A | above 0.47 | above 0.35 |
| B | above 0.38 | above 0.26 |
| C | 0.38 or below | 0.26 or below |
The figures above reflect the thresholds set in the federal regulation. Check the current regulation text if you need exact values for technical or compliance work. The test measures a locked, sliding wheel. Modern cars with anti-lock brakes stop using the grip available just before a wheel locks, which is a different quantity. So treat the traction grade as a rough guide to wet braking ability. It cannot predict stopping distance on a particular vehicle.
What the traction grade does not tell you
- Dry braking: the test runs only on wet surfaces.
- Cornering grip: the test is straight-line braking only.
- Hydroplaning resistance in standing water: the test surfaces are wetted, not flooded.
- Snow and ice performance: UTQG does not test these at all.
- Worn-tire behavior: grip after significant tread wear is not part of the grade.
UTQG and snow
No part of UTQG measures winter traction, so an AA traction grade says nothing about snow or ice. If winter performance matters, look for the three-peak mountain snowflake symbol. It indicates the tire passed a standardized snow traction test. The M+S (mud and snow) marking is based on tread design and does not involve a snow performance test. Many dedicated winter tires carry no UTQG grades at all.
What the treadwear grade means
The treadwear number compares the tire's wear rate with a government reference tire that is assigned a grade of 100. Tires are run in convoys over a fixed public-road test route in Texas for about 7,200 miles, and the manufacturer projects the full wear-out from those results. A grade of 400 means the tire was projected to last four times as long as the reference tire under those test conditions.
Manufacturers assign the treadwear grade based on their own test results and interpretation. Grades are therefore more meaningful when comparing tires within one manufacturer's range than across brands. The number does not convert to miles. Real tread life depends on driving style, inflation, alignment, load, climate and road surfaces. A manufacturer's mileage warranty, if one is offered, is a separate commitment from the UTQG grade.
Is a 420 treadwear grade good?
A 420 grade means the tire's projected wear life was 4.2 times that of the reference tire in the government test. Whether that is good depends on the type of tire and what you compare it with. Performance-focused tires with softer, grippier rubber compounds generally carry lower treadwear grades than touring tires designed for long life. A higher number usually trades away some grip. The grade alone cannot tell you how many miles a 420-rated tire will last on your car. For a more concrete figure, compare tires of the same category from the same brand and check any mileage warranty.
What the temperature grade means
The temperature grade shows how well the tire resists heat buildup and sheds heat at high speed. It is measured on an indoor laboratory test wheel under controlled conditions. Excessive heat can degrade a tire and contribute to failure. Grades are A, B or C, based on the speed the tire sustained in the test.
| Temperature grade | Test speed sustained |
| A | over 115 mph |
| B | 100 to 115 mph |
| C | 85 to 100 mph |
Grade C corresponds to the minimum performance that federal standards require of passenger car tires. The grade assumes correct inflation and no overloading. Underinflation, excess load or sustained excessive speed can cause dangerous heat buildup whatever the grade. The temperature grade is also separate from the speed rating letter in the tire size code. That letter indicates the maximum rated speed under its own test.
Reading common combinations: 500 AA and 600 AA
A marking such as 500 AA means a treadwear grade of 500 and a traction grade of AA. A temperature letter normally follows, as in 500 AA A. A 600 AA tire combines a relatively high treadwear grade with the top wet-braking grade, which is a strong result on both measures. The label still does not show snow capability, dry handling, noise or actual mileage. Also check the temperature letter and the tire's other sidewall markings before treating it as a good fit for your needs.
Using UTQG grades when choosing tires
- Start with the tire size, load index and speed rating specified on your vehicle's tire placard or in the owner's manual. UTQG grades do not replace these requirements.
- Use the traction grade as a first screen for wet braking. AA or A is the stronger choice if you drive often in rain.
- Compare treadwear grades mainly within one manufacturer's lineup, and treat cross-brand comparisons as approximate.
- Check the temperature grade, especially for sustained highway speeds, heavy loads or hot climates.
- For winter driving, look for the three-peak mountain snowflake symbol rather than relying on UTQG.
- For qualities UTQG does not measure, such as dry grip, cornering, snow traction and noise, look for independent test results.
Related articles
Distinguish minimum dual spacing, wheel centerline distance and sidewall clearance
What minimum dual tire spacing means, how it differs from sidewall clearance and axle spacing, and how to read the spec for a dual-wheel truck such as a Chevy dually.
Distinguish REGROOVABLE markings from regrooved and retreaded tires
A REGROOVABLE sidewall marking describes how a tire was built, not what has been done to it. Learn how it differs from regrooved and retreaded tires and what evidence confirms each.
Identify Pirelli PNCS acoustic treatment and distinguish external-noise grades
What Pirelli PNCS means, how to confirm a tire has it, and why the EU external-noise class and dB(A) value measure something different.
Identify Continental FR rim-protector features and verify catalog terminology
What FR means on a Continental tire, where the flange rib sits, how it appears in a size designation, and how to tell it apart from other rim-guard codes.
Interpret MPT, IND, ML, ET and POR tire markings in their documented contexts
What MPT, IND, ML, ET and POR mean on a tire designation, where each code sits, and why IND's axle-role wording differs between Continental, EDIWheel and Trelleborg.
Interpret Yokohama sidewall dots and distinguish tread paint stripes
A red dot on a new Yokohama tire marks its point of maximum radial force variation; a yellow dot marks its lightest point. Learn how they differ from tread stripes.
Decode Goodyear aircraft tire sizes and sidewall information
How to read Goodyear aircraft tire sizes in Three Part, Radial, Metric, Type VII and Type III formats, and how to separate size from other sidewall markings.
Identify blackwall, whitewall and tire-lettering appearance codes
OWL means outlined white letters; BW or BSW means a plain black sidewall. Learn how to decode tire appearance codes and tell whitewalls from tread stripes.
Find an EPREL tire label and check its product identity
How to open a tire's EPREL record from its label QR code, and how to check that the record matches the physical tire and the manufacturer's listing before you compare grades.
Read EU tire-label grades and snow or ice symbols
How to read the revised EU tire label: A–E rolling-resistance and wet-grip grades, noise dB and class, snow and ice pictograms, and what the sidewall shows instead.