What do Treadwear, Traction and Temperature Ratings Mean on Your Tires?
When shopping for tires, there are several items you can compare other than price. Even if you are not in the market for tires right now, the tires on your vehicle are graded based on treadwear, traction and temperature. It might be interesting for you to see what the ratings are on the tires you have now just for the sake of knowing.
The United States government has established the UTQG (Uniform Tire Quality Grading) to assist consumers when they are in the market for tires. The key to using this system is to understand that it is a relative comparison system. In other words, you can compare different brand names, different tread patterns and styles and have a somewhat uniform reference system as to how one tire compares to another.
The UTQG is not a safety rating and not a guarantee that a tire will last for a prescribed number of miles. Under UTQG, manufacturers use three criteria to grade tires: treadwear, traction and temperature.
The information is easily viewable when buying tires. This information is also available when searching for new tires on the internet. The information can be found:
- On the paper label affixed to the tread, or
- On the tire molded into the sidewall
What is the treadwear grade?
The treadwear grade is a comparative rating based on the wear of a tire when tested carefully under controlled conditions. For example the useful tread on a tire graded 400 should last twice as long as a tire graded 200. However, another tire manufacturer may grade a comparable design 300, so a grade of 150 would last just half as long under their grading system. The lesson learned is to not use one manufacturer’s grade versus the other, but instead to compare tire grades within a given brand. Actual treadwear performance can vary tremendously according to the tire’s real-world use. Variations in driving habits, service practices (most importantly air pressure and alignment maintenance), road conditions and climate will also affect tire life.
What are traction grades?
Traction grades represent the tire’s ability to stop on wet pavement as measured under controlled conditions on asphalt and concrete test surfaces. As of 1997, the traction grades from highest to lowest are “AA”,”A”,”B” and “C”. A tire graded “AA” may have relatively better traction performance than a tire graded lower, based on straight-ahead braking tests. The grades do not take into consideration the cornering or turning performance of a tire.
What are temperature grades?
Temperature grades represent a tire’s resistance to heat and its ability to dissipate heat when tested under controlled laboratory test conditions. The grades from highest to lowest are “A”,”B” and “C”. The grade “C” corresponds to the minimum performance required by federal safety standard. Therefore, the “A” tire is the coolest running, and even though the “C” tire runs hotter it does not mean it is unsafe. The temperature grade is established for a tire that is properly inflated and not overloaded.
Does a tire’s treadwear grade guarantee you a certain amount of mileage? The short answer to that is no. Certain manufactures and private sellers might offer their own mileage guarantee. For instance, Michelin might offer an “80,000 mile warranty”. Or, Costco might offer a “60,000 mile warranty” on a certain tire. These guarantees are almost always related to, but not guaranteed by the treadwear grade. Generally speaking, the higher the treadwear grade the higher the mileage you can expect to get from the tire.
How does a mileage warranty work?
Mileage warranties are prorated. If you get 70,000 miles out of a set of tires and you have an 80,000 mile warranty, you will not get a new set of tires for free. In this example, you received 87.5% of the mileage promised (70,000/80,000 = 87.5%). You would be entitled to a prorated adjustment of 12.5% when purchasing a new set of the same brand (aka Michelin, Goodyear, Cooper, etc.) tire.
There are other considerations with mileage warranties. Such as, did the vehicle’s misalignment cause the tires to wear out pre-maturely? Was over or under inflation a factor? Were the tires rotated properly and in a timely fashion?
If you have questions about tires, Postle’s Tire Barn has the answers. Postle’s Tire Barn has been serving the Tuscaloosa and West Alabama area for more than 35 years. We are home owned and home operated. For more information, email us at email@example.com or call us at 205-391-0062.