Volvo XC90 Owner's Manual page 141

Use the parking heater* in cold weather so that
the engine reaches normal operating tempera-
ture more quickly.
IMPORTANT
If the filter fills up it may be incapable of
functioning. Then it can be difficult to start
the engine and there is a risk that the filter
will have to be replaced.
06 Starting and driving
*
Option/accessory, for more information, see Introduction.
Refuelling
06
141