How can customers objectively compare products if all manufacturers boast that theirs are the best? Short answer: ask people that used the product or use a third-party rating. The UTQG is more than a third-party rating - it is a national standard. As practice shows, though, achieving objectivity with it is still a difficult task.
The Uniform Tire Quality Grade, abbreviated UTQG, was designed by the National Highway Traffic Safety Administration of the Department of Transportation to help customers make their choice when they search for new tires. The rating presents three parameters: treadwear, traction and temperature, with a task of providing a comfortable way to objectively compare various products. Whether the UTQG rating achieves this task or not, is more difficult to judge.
Where can I find the UTQG?
The UTQG rating: treadwear, traction and temperature grades.
For a tire to be legally sold in the United States, it must have the UTQG rating imprinted on its sidewall. For instance, the Pilot Super Sport 225/45ZR17 94(Y) XL has the rating of 300 AA A. If you look at your tire, you should be able to find that information on the sidewall, just above the tire size.
The UTQG rating applies to passenger car and light duty truck tires. Winter, trailer, spare and deep-treaded truck tires are not rated.
The UTQG informs about three parameters. First one is tread wear, which occurs as microscopic amounts of rubber are torn off the tire as it rolls on the road. Then there is traction, a parameter which tells how the tire behaves during braking and cornering. Finally, there is temperature, or rather the tire’s ability to dissipate heat, which is generated at high speeds.
Treadwear 400 - four times as much as the test tire.
The treadwear grade tells you about durability. Summer tires usually begin with 10/32” tread depth which is gradually decreased as the tire rolls. With tread torn down to 4/32” depth, the tire should be replaced, and at 2/32” becomes illegal to use.
The tire is tested on the road and its performance is compared to a test tire with a treadwear value of 100. If the same amount of tread is lost after twice a distance in comparison to the test tire, then the tested tire receives a grade of 200. If it lasted four times as long, then it is graded treadwear 400.
Touring tires boast some the largest values, one example being the Continental TrueContact tires with treadwear value of 800. On the other end of the spectrum, there are racing tires, for which treadwear is not that relevant (they may be torn in a single race). Toyo Proxes RR, slick-treaded competition tires, are rated 40. Curiously – the rating allows zero value, and Toyo Proxes TQ, another racing tires, have treadwear value set to 0.
Traction grade A - good traction on wet surfaces
In traction test – simplifying the elaborate procedure – the test tires and the tested ones are inflated and mounted on a skid trailer, pulled by a truck on a wet surface (asphalt and concrete) at 40 mph for some time after which brakes are engaged.
Traction test may be the most controversial of all three conducted. It does not check cornering performance at all or braking on dry surface. Using a system when the tire is mounted on a skid trailer and pulled by a truck, instead of using a passenger car, is also a reason for concern.
The possible grades are C (the worst), B (moderate), A (good) and since 1997 also AA (the best traction). C-rated tires should be driven with extreme caution. The Toyo Proxes RR, competition tires mentioned before, have the traction rated as C – which seems unfair for a high quality competition tire, but it results from the test being conducted on wet surface, on which racing tires should never be used as they specialize in traction on dry. Not surprisingly, the same company’s Proxes T1R are AA-rated, not without the help of its directional tread pattern, which performs admirably on wet surfaces.
Temperature grade A - best there is.
The temperature test measures the ability of a tire to dissipate heat generated at high speeds, and therefore the tire’s ability to maintain structural integrity before damage caused by heat generation results in tire failure. The fully loaded tire is being tested at high speeds, rolling against a test wheel under laboratory conditions.
How useful is the rating?
The Uniform Tire Quality Grade was intended to help the customers make a decision which tire to purchase by providing three parameters that could be used to objectively compare products.
Unfortunately, the rating cannot be considered objective. Treadwear is a phenomenon that occurs after years of driving and which is dependent on road condition, weather, load, condition of the suspension, type of terrain and driving style – which are not taken into account in the tests. Traction is tested on tires mounted on a skid trailer pulled by a track which brakes from 40 mph on wet concrete and asphalt only. It does not tell anything of the tire’s behavior on dry surface, during cornering or even when used on a passenger car. Temperature resistance is also dependent on numerous factions, including ambient temperature which influences tread effectiveness and internal tire pressure.
More importantly though, tests are not conducted by the Department of Transportation, but by manufacturers themselves, or companies hired by them. Therefore, while the UTQG may enable you to somewhat objectively compare products within a brand, bear in mind that the UTQG alone may not be the best tool when comparing products from different manufacturer.