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UTQG ratings explained: what 320 AA A actually tells you

UTQG treadwear, traction, and temperature ratings are stamped on every passenger tire sold in the US. Here's what each grade means, how it's tested, and where the ratings are actually useful — and where they aren't.

The Uniform Tire Quality Grading system (UTQG) is the closest the US tire market has to a standardized spec sheet. It's three numbers, mandated by the NHTSA, that appear on every passenger tire's sidewall. The system has been in place since 1979. It is also widely misunderstood, partly because the three ratings measure very different things and partly because the test method has structural weaknesses that the industry has been working around for decades.

Treadwear

The treadwear grade is a number — usually between 100 and 800 for passenger tires, with track and competition tires sometimes rated as low as 40. The number is a relative index: a tire rated 200 is expected to last twice as long as a tire rated 100, when tested on the same standardized course.

The test course is the West Texas oval — a 400-mile loop in Texas that all UTQG candidate tires must run. Each candidate is run alongside a reference tire whose wear rate is established. The candidate's treadwear grade is the ratio of its wear rate to the reference tire's, multiplied by 100.

The two important caveats:

  1. The rating is a manufacturer self-rating. NHTSA doesn't run the tests. Manufacturers run them on their own and submit results. The system depends on internal consistency within each manufacturer's lineup — and that internal consistency is usually good. But comparing a 400-rated Brand A tire to a 400-rated Brand B tire is comparing two separately-calibrated rulers.
  2. The test is short and hot. The Texas course is hot asphalt; the test is 400 miles. Tires that wear linearly under those conditions can wear non-linearly under colder, wetter, or mixed real-world conditions. Treadwear is a useful relative durability index within a brand. It is a soft guide across brands.

Rule of thumb on what the numbers mean within a single manufacturer:

A real-world translation: a UHP all-season at 500 typically returns 40,000-50,000 miles. A long-life touring tire at 800 typically returns 60,000-80,000 miles. Independent Consumer Reports testing has consistently shown that the relative order of brands by treadwear claim is roughly correct, but the absolute miles delivered vary by 20-30% from the manufacturer's marketing claims.

Traction

Traction is a letter grade — AA, A, B, or C — measuring straight-line wet braking on a controlled surface. The test is two surfaces: wet asphalt and wet concrete. Each is tested at a specified speed. The tire's coefficient of friction during ABS-actuated stops is measured against minimum thresholds.

Most modern passenger tires earn either AA or A. Traction grade C is the legal minimum; tires that low are rare on the US market today. A tire stamped B for traction is below average for wet braking and should be a hard pass for any owner who drives in wet weather.

Important: traction grade measures only straight-line wet braking on a slick surface. It does not measure dry braking, cornering grip, hydroplaning resistance at speed, snow traction, or any other aspect of grip. A AA-rated all-season tire can still hydroplane sooner than an A-rated summer tire — they're different test conditions.

Temperature

Temperature grade — A, B, or C — measures the tire's resistance to heat generated at sustained high speeds. The test runs the tire at progressively higher speeds on a controlled rig until structural failure occurs.

Any performance summer tire is rated A. Touring all-seasons can be either A or B; B is acceptable for typical highway use. Temperature C exists mostly on entry-level economy tires and trailer-only tires.

Reading the stamp

A typical UTQG stamp reads TREADWEAR 320 TRACTION AA TEMPERATURE A. That tire is a mid-grip performance summer or UHP all-season with strong wet braking and good heat tolerance. For comparison:

How to actually use UTQG when shopping

UTQG is most useful as a sanity check within a category. If you've already decided on, say, a performance summer tire in your size, the treadwear numbers across the candidates tell you which one will give you the longest life. Within a category, the relative order is reliable.

UTQG is least useful as a category-crossing comparison. A summer tire with 300 treadwear is not "better" or "worse" than an all-season with 600 — they're built for different use cases. The treadwear difference reflects compound choice, not quality.

Independent test data — Consumer Reports, Tire Rack's own testing, the EU's mandatory wet-grip labels — should be weighed alongside UTQG, especially for traction. UTQG tells you the manufacturer's own benchmark. Third-party testing tells you how that benchmark holds up against direct rivals on the same day.

Frequently asked questions

Does a higher treadwear number always mean longer life?
Within a single manufacturer's lineup, yes — a 800-rated tire will outlast a 400-rated tire from the same brand. Across manufacturers, treat treadwear as a soft indicator. A 600-rated Tire A may not outlast a 500-rated Tire B if Tire A's compound is being optimized differently.
Why don't winter tires have UTQG ratings?
Winter tires are exempt from the UTQG requirement. The Texas test course can't meaningfully measure cold-weather compound performance, so the ratings would be misleading. Winter tires use the 3PMSF symbol instead.
Are AA traction tires safer than A traction tires?
In straight-line wet braking, yes — but the practical difference is small (typically a few feet of stopping distance from 30 mph on wet pavement). Both ratings are safe for normal use; AA is a meaningful upgrade for owners who drive in heavy rain regularly.
Why doesn't my tire have a UTQG stamp?
Light truck tires (LT-prefix sizes), trailer-only tires, deep-snow / winter tires, temporary spares, and some racing tires are exempt from the UTQG requirement. If your tire has none of these characteristics and no UTQG stamp, the tire may be a gray-market import.

Sources

By Mark Bishop · Updated 2026-04-30.