ADAC Study: Winter Tires Lose Grip Fast Below 4mm Tread
Munich – September 10, 2026 -- German auto club ADAC has found that winter tires start losing significant safety performance once tread depth drops below four millimeters, well above the legal minimum of 1.6 millimeters allowed in Germany.
ADAC tested five tires worn down to specific depths
Researchers took five winter tires from different manufacturers and price ranges and used a specialized machine to wear them down to four millimeters and two millimeters of remaining tread. The tires then underwent handling and braking tests on wet and snow-covered surfaces.