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:
It is important to have the vehicle's systems and equipment checked carefully
before driving long distances.
Check that
the engine is running properly and that fuel consumption is normal
there are no leaks (fuel, oil or other fluid)
the brake pedal is functioning properly
tire tread depth and air pressure are at correct levels...
The media player can play videos from USBconnected devices.
Video is not available when the vehicle is moving; only audio will be played.
Video will resume when the vehicle is stationary.
Information on compatible media formats is provided in a separate section...