Porsche 911 Carrera Owner's Manual page 137

A Tire pressure
B Tire temperature
C Tire pressures for cold tires
D Tire pressure for hot tires
E Pressure increase as the result of tempera-
ture increase
F Pressure drop in faulty/leaking tires
1 Required-pressure line
2 Warning stage 1 (from -3 psi to -6 psi
(-0.2 bar to -0.4 bar))
3 Warning stage 2 (from -6 psi (-0.4 bar))
Pressure increase as the result of
temperature increase
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 relationship
between tire pressure and temperature into
account.
Tire pressure specications
Information on tire pressure for public roads can
be found in this Owner's Manual in the Technical
Data chapter or on the tire-pressure plate in the left
door aperture. These values apply to cold tires at
68°F (20°C ) ambient temperature.
135
Controls, Instruments