Porsche Boxster Owner's Manual page 150

Tire pressure function of the on-board
computer
The tire pressure function of the on-board
computer displays the tire pressures (actual
pressure) dependent on temperature in the four
wheels.
You can watch the tire pressure rise as the
temperature increases while driving.
This display is only for information.
f Under no circumstances should the tire
pressures be changed based on this display.
148
Instruments, On-Board Computer, Warnings
Warning!
This display is for informational purposes
only. Under no circumstances should the tire
pressures be changed based on this display.
Changing the tire pressure to incorrect
pressures could adversely affect the perfor-
mance, driving characteristics, and safety of
your vehicle.
f Maintain tire pressures according to the units
indicated on the tire pressure plate, located on
the drivers side door of the vehicle.
Displaying the tire pressure function of the
on-board computer
f Push operating lever up or down until the tire
pressure function of the on-board computer
appears.
(The selection field must be switched off.)
Pressure info in tire pressure menu
In accordance with physical principles, the air
pressure changes as the temperature changes.
The tire pressure increases or decreases by
around 1.5 psi (0.1 bar) for every 18 °F (10 °C)
change in temperature.
The Tire Pressure Monitoring takes this relation-
ship between tire pressure and temperature into
account.
f Please see the chapter "PRESSURE INCREASE
AS THE RESULT OF TEMPERATURE
INCREASE" on Page 156.
You can read the tire pressures to be
corrected in this display.