What does the TREADWEAR marking mean

In the USA, for the convenience of car owners, three types of markings have been approved to help with the selection of tires. If a manufacturer wants to sell its tires on the US market, it simply must apply these markings. If all the necessary markings are applied, the tire is allowed on the market and receives the DOT marking.

Treadwear – tire life

Traction – grip on a wet road

Temperature – resistance to overheating

How is Treadwear tested?

There is an approved closed route on public roads, 400 miles long. To confirm the indicator on this route, a group of four cars drives, one of which is equipped with standard tires. According to the testing rules, drivers change places every 800 miles. This is done to minimize the impact of the driver on the tires and the nature of wear.

In total, the cars travel 7,200 miles, which is 11,500 kilometers. After this distance, experts from the organization check the tire wear and compare the remaining tread depth with the standard tire. At the same time, the life of the standard tire is taken as a factor of 100. Therefore, we see Treadwear 80, 120, 200, 300, 400, and so on. This is not thousands of kilometers, as many believe, but only the ratio of the test tire to the standard one.

Why doesn't it work?

Climate and road type are factors that cannot be ignored. In the USA, conditions differ from ours, and tire life cannot be compared "head-on".

Moreover, standard tires change over time. These are literally different tires of different brands. Therefore, tires of different generations cannot be compared. They can only be compared with different standard tires.

It's also worth noting that manufacturers lay the potential in the tire not for 11,500 km, but for longer, so it's incorrect to compare tires only after this mileage. The tire compound may include several layers of completely different rubber composition, which differs in both characteristics and resource.

But the most important thing is that we often write about the fact that a tire is a compromise of characteristics. Any high advantage will inevitably affect another, possibly more important parameter. A large tire life will inevitably affect traction. That's why racing tires, where traction is crucial, have a very low TREADWEAR index.

It's also worth noting that tire wear is much more affected by the following factors:

• type of vehicle and drive type
• type of road surface
• climate
• road condition

and, of course, driving style.