UTQG is the three-part stamp on your sidewall: a treadwear number, a traction letter, a temperature letter. The treadwear number is the one people use, and the usual advice is to divide it by 100 and treat the result as a multiplier. A 600 lasts twice as long as a 300.
We tested that against the manufacturers’ own warranties. Across 68 tires carrying both a grade and a mileage commitment, the two rise together, but loosely. Tires graded around 600 are warrantied anywhere from 45,000 to 70,000 miles, and several tires with lower grades are backed further than tires with higher ones.
What UTQG is
Uniform Tire Quality Grading is a labelling requirement, not a quality award. Three grades, each measuring one thing and nothing else:
- Treadwear, a number, indexed against a reference tire set at 100.
- Traction, a letter, measuring wet stopping on a locked wheel and nothing else.
- Temperature, a letter, measuring heat resistance at speed.
Light-truck and winter tires are exempt, which matters more than it sounds. We come back to that below.
Who runs the test
Not the government. Manufacturers run the tests themselves, or commission third parties, and report the grades to the Department of Transportation. DOT publishes the grades but not the underlying results.
That is worth stating plainly, because it is easy to read a federal label as a federal measurement. The framework is federal; the number is self-declared within it. There is no independent body checking that a 700 is really a 700.
The treadwear test
The treadwear grade comes from real road use, which makes it sound more trustworthy than a laboratory figure. The details temper that.
A convoy runs a 400-mile circuit in west Texas, 18 times, for 7,200 miles total. Tires are rotated, realigned and pressure-checked every 800 miles so the test tire and the reference tire see identical conditions. At the end, both are measured, and the wear rates are compared.
The reference tire is defined as 100. A tire that wears half as fast grades 200, and so on.
Two things follow from that method:
7,200 miles is a small sample of a tire’s life. Most tires are expected to run 50,000 to 75,000. Everything beyond the tested distance is extrapolation, and extrapolation from the first tenth of a curve is a strong assumption about the other nine.
Each manufacturer extrapolates its own result. The test is standardised; the projection from it is not audited. This is the source of the caveat you always see about comparing across brands, and it is the thing we can now show rather than assert.
Does the grade match the promise?
A manufacturer publishes two numbers about how long a tire will last: the UTQG grade, and the treadwear warranty they will pay out against. If those agree, the grade is carrying real information. If they don’t, one of them is describing something else.
At the level of whole categories, they agree closely:
| Category | Tires | Median grade | Median warranty | Miles per grade point |
|---|---|---|---|---|
| Highway-Terrain | 20 | 700 | 70,000 | 100.0 |
| Touring | 7 | 640 | 65,000 | 101.6 |
| On-Road AT | 20 | 620 | 60,000 | 96.8 |
| Off-Road AT | 11 | 600 | 55,000 | 91.7 |
| Rugged AT | 6 | 570 | 50,000 | 87.7 |
Swipe the table sideways to see every column.
Grade times 100 lands close to the warranty at the top of that table and drifts below it toward the bottom. An aggressive tire with the same grade as a highway tire gets a shorter commitment, which is a sensible thing for a manufacturer to do and not something the grade itself tells you.
The same grade, different promises
Category medians smooth things out. Individual tires don’t.
Among the 17 tires graded around 600, warranties run from 45,000 to 70,000 miles. The Hankook Dynapro HPX is backed for 70,000. The Toyo Open Country R/T Trail, carrying the same grade, is backed for 45,000. That is a 56% difference between two tires whose sidewalls make the same claim.
It also runs the other way. The Nitto Terra Grappler G3 grades 600 and carries a 70,000-mile warranty. The Kumho Road Venture AT52 grades 680, higher, and carries 55,000. A buyer comparing those two by their treadwear numbers would reach the wrong conclusion about which one the manufacturer expects to last.
Across all 68 tires, the ratio of warranty miles to grade points runs from 75 to 156. A twofold spread in what a single grade point is worth.
So the standard advice, that grades are only comparable within a brand, is right. The useful version is more specific: a difference of 50 or 100 points between two brands tells you nothing. A difference of 300 probably does.
Where the grade doesn’t exist
Light-truck tires are exempt from UTQG, and that exemption covers a great deal of what gets sold on trucks.
| Category | Sizes | With a grade |
|---|---|---|
| Touring | 261 | 100% |
| Highway-Terrain | 612 | 75% |
| On-Road AT | 751 | 65% |
| Off-Road AT | 712 | 32% |
| Rugged AT | 416 | 22% |
| Commercial AT | 58 | 10% |
| Mud-Terrain | 219 | 0% |
Not one of the 219 mud-terrain sizes we hold carries a grade. Nor does roughly two thirds of the off-road all-terrain range.
The practical trap: you compare two tires by treadwear grade on a retailer’s listing page, decide, then buy the LT size. The number you compared may not apply to what arrives. Check the grade for the specific size, not the model.
Traction grade
The traction letter measures one narrow thing: straight-line wet stopping with the wheel locked. A skid trailer is towed at 40 mph across wet asphalt and concrete, the brakes are locked briefly, and the friction coefficient is recorded.
| Grade | Asphalt | Concrete |
|---|---|---|
| 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 |
What it does not measure: dry braking, cornering grip, hydroplaning resistance, or anything at all in the wet once the wheel is rotating. Since nearly every vehicle on the road has ABS and therefore never locks a wheel, the test condition is one you will rarely experience.
Read it as a floor rather than a ranking. A tire graded C has demonstrated poor wet friction and is worth avoiding. The gap between an A and an AA tells you much less.
Temperature grade
An indoor test. The tire runs against a high-speed drum and the grade records the speed it sustains without failing.
| Grade | Sustained speed |
|---|---|
| A | over 115 mph |
| B | 100 to 115 mph |
| C | 85 to 100 mph |
C is the legal minimum for sale in the United States, so this grade separates tires that clear the bar from tires that clear it comfortably. It is the least useful of the three for choosing between tires, and the most useful for spotting a tire that shouldn’t be on a vehicle that cruises at speed.
How to actually use it
The grades are worth reading. They are not worth the precision people give them.
- Within one manufacturer’s range, treadwear grades are a fair guide to which tire is built to last longer. Same test, same extrapolation, same assumptions.
- Across brands, treat differences under 100 points as noise. Our data shows tires with identical grades carrying warranties 25,000 miles apart.
- Check the size, not the model. The grade on the listing may not exist for the size you’re buying, particularly in LT fitments.
- Use the warranty alongside it. It is the number the manufacturer will actually pay out against, which gives it a discipline the grade lacks.
- Avoid a C traction grade if the tire will see wet roads. Beyond that, the letter tells you less than the treadwear number does.
For what actually determines how long a set lasts once it’s on the vehicle, see our guide to making tires last longer.
Key takeaways
In short
- Manufacturers run the UTQG tests themselves and report the grades. The framework is federal; the number is self-declared within it.
- The treadwear grade extrapolates a 7,200-mile test out to a full tire life, and each manufacturer does its own extrapolation.
- Across 68 tires, grade and warranty rise together, but tires graded around 600 carry warranties from 45,000 to 70,000 miles.
- The Nitto Terra Grappler G3 grades 600 with a 70,000-mile warranty. The Kumho Road Venture AT52 grades 680 with 55,000.
- By category the two line up well: grade times 100 lands near the warranty for highway tires and drifts below it for aggressive ones.
- Both numbers come from the same company, so their agreement may reflect one judgement expressed twice rather than two measures converging.
- No mud-terrain size carries a grade at all, and only a third of off-road all-terrain sizes do. Check the size, not the model.
- The traction grade measures locked-wheel wet stopping only. It says nothing about cornering, hydroplaning or dry braking.
Common questions
What does the UTQG treadwear number actually mean?
It is an index against a reference tire set at 100, derived from a 7,200-mile convoy test in west Texas and extrapolated out to a full tire life. A tire graded 600 wore six times slower than the reference over the tested distance. The extrapolation beyond 7,200 miles is the manufacturer’s own, which is why grades from different brands are not directly comparable.
Is a higher UTQG number always better?
Within one manufacturer’s range, a higher number does mean a tire built to last longer. Across brands it often doesn’t hold. In our data the Nitto Terra Grappler G3 grades 600 and carries a 70,000-mile warranty, while the Kumho Road Venture AT52 grades 680 and carries 55,000. Treat differences under 100 points between brands as noise.
Does the government test tires for UTQG?
No. Manufacturers run the tests themselves or commission third parties, then report the grades to the Department of Transportation. DOT publishes the grades but not the underlying results, and no independent body verifies that a given grade was earned.
Why doesn’t my tire have a UTQG rating?
Light-truck and winter tires are exempt. Across the sizes we hold, none of the 219 mud-terrain sizes carries a treadwear grade, only 22% of rugged all-terrain sizes do, and 32% of off-road all-terrain sizes. If you compared two tires by grade on a listing page and then bought an LT size, the number you compared may not apply to what you received.
What does a traction grade of A mean?
That the tire achieved a friction coefficient above 0.47 on wet asphalt and 0.35 on wet concrete, with the wheel locked, towed at 40 mph. It says nothing about cornering grip, hydroplaning resistance or dry braking, and since nearly all vehicles have ABS, the locked-wheel condition is one you will rarely meet. Read it as a floor: avoid C, and don’t read much into A against AA.
Can I use UTQG to predict how many miles I’ll get?
Not reliably. Across 68 tires carrying both figures, the ratio of warranty miles to grade points ranges from 75 to 156, a twofold spread. The treadwear warranty is the better number for this, because it is a commitment the manufacturer has to honour rather than a projection they published.
Where this comes from. UTQG grades are read from manufacturer specification sheets covering 3,198 individual sizes across 94 tires, with a median taken per tire across whichever of its sizes carry a grade. Warranty figures come from published warranty statements for 92 tires, of which 68 carry both a grade and a mileage commitment. Test procedures and grade thresholds are as set out in the federal Uniform Tire Quality Grading standard.
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