The invention concerns a tire pressure adjusting system for setting the pressure in a tire mounted on a vehicle. A pressure source assigned to the vehicle and at least one connecting line are provided, with which the pressure source can be connected to a tire. The tire can be mounted on a rim. Within the space formed between the tire and the rim, a dividing means is provided, with which the space can be divided into two chambers. In order to reduce the time period for a change in the tire pressure, a means of limitation be provided, with which the volume expansion of a chamber can be limited to a maximum volume value that can be set, and that to change the pressure of the tire only the pressure in one of the two chambers needs to be changed.