UTQG Ratings Explained: Treadwear, Traction, Temperature

What UTQG is

UTQG stands for Uniform Tire Quality Grading. It is a federal system that gives many passenger tires three grades: treadwear, traction and temperature.

The grades are molded into the sidewall. The rule places them between the tire's maximum section width and the shoulder.

Our guide to reading a tire sidewall shows where this sits among the other markings.

Who assigns the grades

The tire maker does. The regulation says manufacturers and brand name owners must provide the grading information for each tire, based on controlled testing.

Consumer Reports puts it plainly: manufacturers grade the tires themselves. Tires must meet their assigned grades, but the scoring is not precise, and a maker can choose how conservative to be.

That is the main reason to treat UTQG as one clue and not a verdict.

Treadwear

The treadwear grade is a number, in multiples of 20, such as 80, 120 or 160. It compares how a tire wears against a reference.

The regulation gives the example that a tire graded 150 would wear one and one-half times as well on the government course as a tire graded 100. The test is run on a government course in Texas.

Higher means longer wear in that comparison. A tire graded 200 is expected to wear about twice as long as one graded 100 under the same test conditions.

It is not a mileage figure

Treadwear is not a mileage projection. Continental states that it is wrong to link treadwear grades with projected tire mileage.

The regulation adds that relative performance depends on actual use. It may depart significantly from the norm because of driving habits, service practices and differences in road characteristics and climate.

Traction

The traction grade covers wet stopping. The letters, from highest to lowest, are AA, A, B and C.

The tests use locked-wheel braking on wet asphalt and concrete test surfaces at 40 mph. The tire is graded on how well it stops.

The regulation includes a warning on this point. The traction grade is based on straight-ahead braking traction tests, and does not include acceleration, cornering, hydroplaning, or peak traction characteristics.

So AA is not a measure of overall grip. It is a measure of one test, straight-line braking on wet test surfaces.

Temperature

The temperature grade describes how well a tire resists heat. The letters, from highest to lowest, are A, B and C.

The test runs the tire on an indoor laboratory wheel at stepped-up speeds until it fails or the test is complete.

Grade C corresponds to a level of performance that all passenger car tires must meet under the Federal Motor Vehicle Safety Standard No. 109. So C is the minimum.

The grade assumes the tire is properly inflated and not overloaded. The regulation spells this out. Heat is a reason to check your pressure against the label on the driver's door or in your owner's manual.

Tires without grades

Some tires are not graded at all. The rule does not apply to deep tread tires, winter-type snow tires, space-saver or temporary spare tires, and tires with nominal rim diameters of 12 inches or less. Limited-production tires are also exempt. The rule defines them with several limits, including no more than 15,000 tires a year of the same design and size.

If you are shopping for winter tires, do not be surprised if the UTQG fields are blank. Our guide to all-season, all-weather and winter tires explains what to look for instead.

How to use the numbers

Use UTQG to compare tires you are already considering, and stay cautious.

Compare treadwear within one maker's range before you compare across brands. Consumer Reports notes that although the ratings are on the sidewall, comparing brands is still difficult.

Look at traction and temperature as a floor. Most all-season tires achieve a temperature grade of A, Consumer Reports says, so the letter may not separate them.

Do not use UTQG as a substitute for other information such as warranty terms, independent test results and whether the size matches your vehicle's specification. It also does not replace checking the load index and speed rating. See our guide on load index and speed rating.

Reading the numbers side by side

Treadwear works as a ratio. By the regulation's own example, a tire graded 150 wears one and one-half times as well on the government course as a tire graded 100. By the same logic, a grade of 300 is twice a grade of 150.

That comparison holds for the test course. It is the reason Continental warns against turning the number into miles.

Why not compare freely across brands? Consumer Reports says the scoring is not precise, which lets companies approach grading strategically according to their marketing plans. A treadwear grade from one maker may therefore not line up neatly with a grade from another.

What UTQG leaves out

The grades cover three narrow things. Read the limits as carefully as the letters.

Treadwear is a comparison on a government course, not a prediction of how long your tires will last. The regulation says actual results depend on driving habits, service practices, road characteristics and climate.

Traction covers straight-ahead braking on wet test surfaces. The regulation lists what it leaves out: acceleration, cornering, hydroplaning and peak traction.

Temperature covers heat resistance on a laboratory wheel, for a tire that is properly inflated and not overloaded.

The three grades measure treadwear, wet braking traction and heat resistance only. They do not rate snow or ice grip, ride comfort or noise. Consumer Reports concludes that consumers need even more, and better, information than UTQG provides when buying a tire.

From grades to a purchase

Start with the size on your sidewall or driver's door placard. Then use the tire finder to see tires and retailers for it. If you are weighing a different size, the tire size calculator shows how it changes diameter and speedometer reading.

Grades are assigned tire by tire. Two different tires in the same size, such as 235/65R17 or 225/65R17, can carry different UTQG grades.