Checking Tyre Pressure; Adjusting Tyre Pressure - Volvo XC90 2018 Owner's Manual

WHEELS AND TYRES

Checking tyre pressure

Correct tyre pressure helps to improve driving
stability, saves fuel and extends the service life of
the tyres.
Tyre pressure decreases over time, this is a natu-
ral phenomenon. Tyre pressure also varies
depending on ambient temperature. Driving on
tyres with tyre pressure that is too low could
result in the tyres overheating and being dam-
aged. Tyre pressure affects travelling comfort,
road noise and driving characteristics.
Check the tyre pressures monthly. Use the tyre
pressure recommended for cold tyres in order to
achieve optimal tyre performance and optimal
wear. Tyre pressure that is too low or too high
may cause uneven wear on the tyres.
WARNING
Tyre pressure that is too low is the most
•
common cause of tyre failure and may
result in serious cracks in the tyre, the
tread loosening or the tyre exploding, with
unexpected loss of control of the car and
increased risk of personal injury.
Tyres with pressure that is too low reduce
•
the load capacity of the car.
Cold tyres
The tyre pressure must be checked when the
tyres are cold. Tyres are considered cold when
542
they have the same temperature as the surround-
ing air. This temperature is normally reached
when the car has been parked for at least three
hours.
After having driven approximately 1.6 km (1 mile)
these tyres are considered as warm. If you have
to drive further than this to inflate the tyres, first
check and record the tyre pressure and inflate to
a suitable tyre pressure when you arrive at the
pump.
When the outside temperature changes, the tyre
pressure also changes. A decrease in tempera-
ture of 10 degrees causes the tyre pressure to
decrease 1 psi (7 kPa). Check the tyre pressure
regularly and adjust to the correct pressure,
which is specified on the car's tyre information
decal or certification label.
If you check the tyre pressure when the tyres are
warm then you must never release any air. The
tyres are warm due to driving and it is normal for
the pressure to increase above the recom-
mended pressure for cold tyres. A warm tyre with
tyre pressure equal to or below the recommenda-
tion for cold tyres may have a pressure that is far
too low.
Related information
Adjusting tyre pressure (p. 542)
•
Recommended tyre pressure (p. 543)
•
• Tyre pressure monitoring system* (p. 544)
Tyres (p. 538)
•

Adjusting tyre pressure

Tyre pressure decreases over time, this is a nat-
ural phenomenon. The tyre pressure must there-
fore sometimes be adjusted in order to maintain
the recommended tyre pressure.
Use the tyre pressure recommended for cold
tyres in order to achieve optimal tyre performance
and optimal wear.
NOTE
To avoid incorrect tyre pressure, the pressure
should be checked on cold tyres. "Cold tyres"
means the tyres are the same temperature as
the ambient temperature (approx. 3 hours
after the car has been driven). After a few kil-
ometres of driving, the tyres warm up and the
pressure increases.
1. Remove the cap from the valve on one tyre
and then press the tyre pressure gauge
firmly down onto the valve.
2. Inflate the tyres to the correct pressure, see
the decal on the door pillar on the driver's
side showing the recommended pressure for
factory fitted tyres.
* Option/accessory.