Tread wear indicators - Cross ribs evenly spaced around the circumference of the tire in the main longitudinal tread grooves which become level with the tread surface when the remaining tread depth is down to approx. 1.6mm. Continental acknowledges that 1.6 mm (2/32”) is the most widely accepted minimum tread depth standard at which tires should be removed from service.
This standard has been adopted as a legal regulation by many of the world’s national transportation authorities.
Continental recommends the following tread depths for tire replacement:
summer tires 3 mm - more
winter tires 4 mm - more