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:
(Certain markets only.)
Call a contact in the phone book, have a text message read aloud or dictate
short messages using voice commands to a Bluetoothconnected phone.
To access a contact in the phone book, the voice command must contain the contact
information entered in the phone book...
Settings that have been saved for one or more driver profiles can be reset
when the vehicle is stationary.
NOTE
Factory Reset is only possible when the vehicle is stationary.
Tap Settings in the Top view.
Tap System Factory Reset
Reset Personal Settings...