What Is The UTQG Rating On Tires?
Why Uniform Tire Quality Grade (UTQG) Standards were developed
Selecting quality tires goes beyond purchases that fall within your budget. For a consumer, there are several other desirable qualities impacting the purchase process. Some of these features include relative treadwear, temperature capabilities, and traction (UTQG Rating).
Uniform Tire Quality Grade (UTQG) is a system developed by the US Department of Transport to help car owners make informed decisions and make sufficient comparisons between brands before purchasing new tires.
Typical UTQG codes contain 3-digit numbers followed by two letters, e.g. 400 A A. UTQG codes are assigned after manufacturers conduct tests based on the guidelines provided by National Highway Traffic Safety Authority (NHTSA). UTQG codes are typically found on the sidewall of the tire or on the purchasing retail stickers.
Measuring System of the Department of Transport and National Highway Traffic Safety Authority
The UTQG system that was developed by the department of transport makes it mandatory for manufacturers to test and assign UTQG codes to all passenger tires. UTQG ratings are exempt for light trailers, temporary spares, and winter tires.
Whereas NHTSA does not conduct actual tests, the authority has the right to inspect tire data and extend any fines for notable inconsistencies. The measurement system is used to test and establish treadwear ratings, traction quality, and temperature/heat resistance rating.
The wear rate of new tires is conducted in reference to a Course Monitoring Tire (CMT) data. Typically, the course monitoring tire has a designated grade of 100, calculated over a 30,000-mile service life. Test tires are driven on a convoy of vehicles through a 7,200-mile stretch, after which the wear and tear results are compared to those of the CMT. Treadwear values are checked at regular intervals, during and after the test.
Tires with higher treadwear ratings tend to be more durable compared to those with lower values as friction coefficients decrease with increased ratings.
The traction grade of new tires is conducted by installing the tires on a skid trailer axle. A truck is then used to pull the skid trailer over wet concrete and asphalt surfaces at a constant speed of 40 mph. Trailer brakes are then locked momentarily, with sensors fitted on the trailer recording the braking g-forces at every stop.
|Traction Grades||Asphalt g-Force||Concrete g-Force|
|C||Less Than 0.38||0.26|
Traction grades are ranked from AA (highest rating), A, B and C (lowest rating) and are usually based on the straight line wet coefficient of traction. Traction grades do not reflect the tire’s dry cornering capabilities or high-speed hydroplaning characteristics.
Temperature (Heat Resistance) Rating
This is an indicative test to quantify the amount of heat generated and dissipated by the tire over its operating time. The measurement is conducted by running an inflated tire against a large diameter, high-speed test wheel. Comparative data from the tests are then used to grade tires as A (high resistance), B and C (low resistance).
|Temperature Grades||Speeds in mph|
|B||Between 100 to 115|
|C||Between 85 to 100|
A rated tires are able to perform well at speeds above 115 mph, B rated tires at 100 to 115 mph and grade C at 85 to 100 mph.
How To Read UTQG Numbers (Example)
UTQG codes have a 3-digit numerical code, followed by two letters. A tire with a code 300 A B decodes as the following.
- 300 represents the treadwear rating, implying that the tire will be three times more resistant to wear and tear as compared to the Course Monitoring Tire, whose standard rating is 100.
- A corresponds to tire traction grade. This implies that the tire has superior traction grades.
- B represents the temperature or heat resistance grade. B rating means that the tire has good heat dissipation properties at operating speeds between 100 and 115 mph.
What is a good UTQG rating?
A good UGTC rating is one in which the tire has a higher resistance to treadwear, superior traction and higher resistance to heat.
What is the highest UTQG rating?
A rating of 820 UTQG, Michelin Defender is considered the highest rated tire. It comes with a 90,000-mile warranty and boasts of longer-lasting tread life. High-performance, best-grade tires possess an AA traction rating and A temperature resistance rating.