What is TWI (Tread Wear Indicator) and its significance?
Most tyres have tread wear indicators, usually six or more small ribs across the bottom of the main tread grooves. For motorist the remaining tread depth of rubber on tyre is one of the important aspect to be closely watched to ensure safety of the vehicle, particularly on wet road conditions and high speeds. In India as per CMVR (Center Motor Vehicle Rule) the non skid depth (NSD) shall not be less than 0.8 mm. in case of two wheeler and three wheeler and 1.6 mm. in case of other motor vehicles below the TWI (Tread Wear Indicator) in the tyre”. And this is the minimum tread depth at which the tyre needs to be removed or replaced for safe driving.
