ÖAMTC study confirms critical safety threshold for winter tire tread

An investigation by the Austrian Automobile, Motorcycle and Touring Club (ÖAMTC) and international partners has confirmed that a four-millimeter tread depth is a critical threshold for winter tire safety. The study found that tire performance and safety reserves decrease measurably once tread falls below this level.

Contrary to common assumptions, the most significant loss in stability and braking performance occurred on wet roads due to aquaplaning, rather than on snow or ice. At a four-millimeter tread depth, water displacement capacity dropped by an average of 25 percent compared to new tires. When tread reached two millimeters, water drainage capacity fell by more than 50 percent, significantly increasing the risk of aquaplaning.

The research, which tested five common winter tire models across various price segments, noted that even premium tires could not compensate for physical wear through advanced rubber compounds. As tread depth decreased, high-end models lost their performance advantages over budget-segment tires.