Volvo XC90: Wheels and tires / Tread wear indicator
The tread wear indicator shows the status of the tire's tread.

The tread wear indicator is a narrow elevated strip running across the tire's
longitudinal tread grooves. The letters TWI (Tread Wear Indicator) are visible on
the side of the tire. When approximately 1.6 mm (1/16 inch) is left on the tread,
the tread will be at the same height as the tread wear indicator. Replace the tire
as soon as possible. Tires with low tread offer very poor traction in rain or snow.
Tires with tread designed to roll in only one direction are marked with an
arrow on the sidewall.
The arrow shows the tire's direction of rotation.
The tire should maintain the same direction of rotation throughout its service
life...
The following is a glossary of tire-related terms.
The tire suppliers may have additional markings, notes or warnings such as standard
load, radial tubeless, etc...
Other information:
Regularly check the brake system components for wear.
To keep the vehicle as safe and reliable as possible, follow the Volvo service
schedule specified in the Warranty and Maintenance Records Information booklet.
After replacing brake pads and brake discs, braking effect is not adapted until
they are "broken in" by driving a few hundred kilometers (miles)...
The media player can play audio from external audio sources connected via
USB port or Bluetooth. It can also play video format via the USB port.
When the vehicle is connected to the Internet, it is also possible to listen
to web radio, audio books and to access music services via apps...