Optimum adjustment of tire pressure is necessary for the following reasons:
For this, the physical principles should be observed in combination with pressure and temperature.
The following rule of thumb applies: So a temperature change for every +/- 10 ºC or +/- 18 ºF relates to an increase or decrease in tire pressure of roughly +/- 0.1 bar or 1.4 psi. Please refer to the temperature chart below.
Temperature chart
The tire pressures specified by the manufacturer apply for summer and winter operation, irrespective of the temperature. However, it must be observed that due to the seasonal temperature differences, the tire pressures should be checked frequently.
Cold Tire pressure
If the tire air temperature is the same as the current ambient temperature, this is referred to as cold tire pressure. The tire pressures should only be changed with a cold tire pressure on vehicles without the electronic tire pressure label.
Warm Tire pressure
During longer trips at higher driving speeds the tire warms up due to the friction with the road surface.
The temperature of the tire increases as a result and this is accompanied by an increase in tire pressure.
If there is a significant difference between ambient temperature and tire air temperature this is always referred to as warm tire pressure. Avoid changing the tire pressures when the tire is warm on vehicles without the electronic tire pressure label.