Cold inflation pressure

The tire pressure is the pressure in a pneumatic tire.

The tire pressure is critical to the usefulness of a pneumatic tire. It is therefore adjusted by default and must be checked regularly to maintain the functioning and adjusted if necessary. The tire pressure can also be increased by heating during operation. Incorrect tire pressure leads to premature wear or failure of the tire. That is why increasingly come tire pressure monitoring systems in cars are used. In addition, the tire pressure can significantly affect the performance of a vehicle. If in doubt, so you should orient to the prescribed specifications of the respective vehicle and / or tire manufacturer ever.

The tire pressure is indicated in the unit bar. It is customary not specify the absolute pressure, but the pressure relative to the ambient pressure ( air pressure). The tire pressure specification 2.7 bar thus means the tire pressure to 2.7 bar above ambient pressure of about one bar. The absolute tire pressure so would be 3.7 bar. The tire inflation at gas stations make it the motorist easy, in which they only the relative tire pressure (ie the pressure ) display in bar, which is also called in the vehicle documents.

The tire pressure data of the vehicle or tire manufacturers always refer to the " cold" tire. Thus, the fact it is meant that the tire heats with increasing travel distance and speed. In practice, can be regarded as "cold" a car tire by 10 km route at a moderate pace yet. If the tire pressure checked by a fast motorway driving, the tire filling ( air or nitrogen) has expanded due to heating and the tire pressure increased by 0.3 bar.

Deviations from the tire pressure to the vehicle or tire manufacturer may be functionally justified. Here are three examples:

• An increased tire pressure reduces at car tire rolling resistance and therefore reduces fuel consumption.
• For SUVs, construction and agricultural machinery, the tire pressure is lowered to increase the footprint of the tire. This can transfer more traction on the ground drive wheels, while preserving the vertical force exerted by the tire ground pressure is reduced.

For the filling of the tire, either air or nitrogen is used. The advantage of a nitrogen gas is very controversial in car tires. Supposedly keeps the tire pressure better than with an air filling. However, the differences are negligible (see also the case of tires gas) for the ordinary operation of a car tire.

The nitrogen filling of the tire is usually indicated by a colored valve cap. A refill the tire with air is no problem; since air consists of 78 percent nitrogen. For the operational safety of a car tire is not the choice of the filling gas decisive but regular inspection and correction of air or nitrogen pressure.