The narrow grooves that run lengthways across the tyre's tread pattern are tread wear indicators. On the side of the tyre are the letters TWI1.
Important
- Tyres should be changed before wearing them down to the tread wear indicators to avoid poor traction in rain and snow.
- Volvo recommends that winter tyres have a greater tread depth than 3 millimetres (1/8 inch) and summer tyres 1.6 millimetres (1/16 inch).