Volvo XC90 Owner's Manual page 171

07 Wheels and tyres
General
Summer and winter wheels
The arrow shows the tyre's direction of rotation
When summer and winter wheels are changed
the wheels should be marked with which side
of the car they were mounted on, for example
L for left and R for right. Tyres with a tread pat-
tern which are designed to only turn in one
direction have the direction of rotation marked
with an arrow. The tyre must always rotate in
07
the same direction throughout its lifespan.
Tyres should only be switched between front
and rear positions, never between left and
right-hand sides, or vice versa. If the tyre is
mounted incorrectly, the car's braking charac-
teristics and capacity to force rain, snow and
slush out of the way are adversely affected.
170
Tyres with the greatest tread depth should
always be fitted to the rear of the car (to
decrease the risk of skidding).
Contact an authorised Volvo workshop if you
are uncertain about tread depth.