UTQG (Uniform Tire Quality Grading) rating is a system used to grade tires based on their treadwear, traction, and temperature resistance. It was established by the US Department of Transportation (DOT) to provide consumers with information about a tire’s performance characteristics.
The rating basically gives you a set of numbers and letters, telling you about the grading of the tire. For example, if it’s 400 AA A, the first number tells you about the tread wear rating (the more the better), the second “AA” tells you about the traction rating, and the third is the temperature rating. You can find this rating on your sidewalls.
UTQG Grading
Let’s discusses all the rating system categories which include Tread-wear, Traction and Temperature.
Treadwear
This rating is decided by calculating the tread wear rate of the tire on a government-specified course, and then comparing it with the reference tire, and it ranges between 100 to 800, where with higher number, longer tread life is expected.
For example, if a tire has a tread wear rating of 200, it means that its expected to last, roughly, twice as long as the reference tire.
This rating does not equate to that exactly, meaning, a rating of 200 would not always mean a tire can last twice as much. That’s because for one, the reference tire is a totally different tire which was tested with so many variables we don’t know about including temperature, road conditions and driver’s style.
Moreover, even though mostly tires last above 40k miles, the UTQG only tests the reference tires for 7200 miles.
Related Read: How to improve tread life?
Traction Rating
Traction rating is based on a tire’s ability to stop on wet pavement and is calculated by braking/locking the tire on wet roads and measuring the resultant g forces in return.
The more g forces the better. That’s why tires with AA grade are capable of showing a better traction compared to A, B and C. You can find how much g forces they exhibit by looking at the table below.
| Traction Grade | G-Forces Calculated |
| AA | Greater than 0.54 |
| A | Between 0.47 and 0.54 |
| B | Between 0.38 and 0.46 |
| C | Less than 0.38 |
The braking test is much more scientific. The test wheels are attached to a trailer. The same trailer is used for all tests to control for the vehicle weight, power, balance, etc. It is accelerated up to 40mph on a wet asphalt road, and the brakes are applied. Sensors measure how much the tires “grab” by calculating the force and the coefficient of friction.
Temperature rating
Temperature rating is based on a tire’s ability to dissipate heat under controlled laboratory conditions.
Tires are tested by seeing how fast they can go without experiencing any structural failure due to heat dissipated.
Tires with an A rating have the best temperature resistance, followed by B and C, where C is the lowest rating.
| Temperature Grade | Speed (miles/hour) |
| A | Greater than 115 |
| B | Between 100 and 115 |
| C | Between 85 and 100 |
They just spin a wheel at high speeds until it fails. Then they lower the speed and try again. The speed that doesn’t cause it to fail is the rating.
The manufacturer will often have already done a series of speed tests and determined the car’s speed rating, so the lab can simply double-check to make sure that the speed rating is accurate.
How to Use UTQG Rating?
Well, although it’s a good way to tell how much speed a tire can reach and how good it is on wet roads, in terms of braking, it’s not accurate enough in terms of tread wear.
As I’ve already discussed, there are a lot of variables between the tire you are considering and the reference tire. For one, it’s not the same tire. Its a big one.
And along with that, it only ran for 7k miles, with different driver, on different roads, temperature and so on…
There are just so many variable involved.
But yes, this rating can be useful to compare two tires from the same manufacturer. For example if I am considering Goodyear Assurance All Season with the tread wear rating of 600, and the Goodyear WeatherReady of rating 500, I can tell that the Assurance would be able to last longer.
To Sum up
The UTQG tells you a lot about the tire’s traction abilities on wet, and is a way of telling what type of tread it is.
Though since the rating is very vague, there’s not much you can get out of them, and that goes especially for tread wear rating.
A much better way to anaylze your tire’s tread wear, is to just check how fast the rubber burns off with a tread wear test. You can do this with a penny.
