A warning strategy determines in a mutually separate manner the different effects that may occur in a tire and allows the increments and their priority in the display or indication for the driver to be evaluated in a mutually separate manner. This strategy occurs in connection with a sensor which can transmit at least the outside temperature and, preferably, also the barometric pressure to an evaluation device for detecting tire inflation pressure and tire temperature. As a result, in addition to an air loss monitoring function, the load capacity of the tire can also be evaluated at least as a function of the outside temperature. The evaluation device receives further input signals, such as the vehicle velocity, the tire contact area and/or the vehicle load, whereby also a dynamic tire stress can be taken into account as an indication or display for the driver.