Abstract
It was shown that air suspension bellows are suspension elements where load and spring values can be controlled. Pneumatic suspension with level control allows soft springing of the vehicle body, which is due to the absence of static spring lightening (stroke) as a result of the load differential between full load and weight when empty. The natural frequency of the body remains essentially constant for the whole loading range of the air suspension bellow, since it is possible that the demand for a constant ratio between spring value and body weight can be largely realised with air suspension bellows.