What does the designation “TWI” (Tread Wear Indicator) mean?

The designation "TWI" stands for Tread Wear Indicator, which is a standardized marking on tires to show the level of tread wear. In Germany and many other countries, it helps drivers easily identify when the tire tread has worn down to the minimum legal depth, usually 1.6 millimeters. When the tread reaches the TWI level, it means the tire no longer provides safe grip, especially on wet roads, and should be replaced to ensure safe driving and comply with traffic regulations. The other options, like indicating a recut profile or tubeless tires, are unrelated to the TWI marking.