Air Suspension is a type of shock absorber that uses compressed air from an
engine driven or electric air compressor to perform damping and other suspension functions.
The compressed air is individually pumped to each shock. Each shock uses a chamber of air that can replace the spring,
the damper or both. The air is used as a cushion in the chamber to absorb energy and vibrations.
Sensors measure certain parameters and an ECU determines how the quantity of air
and the psi (pounds per square inch) that is required for each chamber.
Front air suspension from a Porsche Panamera
Air suspension on an Audi A8
The amount of air can be adjusted and the pressure can be adjusted. The chamber can have 1. a low quantity
of air with a low psi 2. a low quantity of air with a high psi 3. a large quantity of air with a low psi
4. a large quantity of air with a high psi or any combination in between.
Even the low psi will be relatively high to be used for suspension damping. The benefits of air suspensions are listed
and explained below.
The ride quality is extremely smooth when compared to conventional springs as compressed air is used to absorb
irregularites on the road. This is perfect for providing a soft and comfortable ride for passengers but by adjusting the
air pressure the suspension can be stiffened for a sport setting.
Some vehicles adjust their height (ground clearance) automatically depending on
various driving conditions and others allow you to set the height of your vehicle quite easily from inside the vehicle. The
amount of air can easily be reduced from the four chambers to lower the vehicle. The difference between the highest and lowest
setting is around four to five inches.
When there is heavy cargo on one side of the vehicle or if one side of the road is slightly higher than the other. Sensors
constantly monitor the height of the vehicle and the amount of air is increased or decreased in any one of the absorbers to
keep the vehicle level. The ride, pitch and roll of the vehicle can be consistent in spite of heavy loads because of the
flexibility of changing the air quantity/pressure.
Other benefits are that they can allow a wider turning range for the tires because there is no spring and the self
levelling feature can be used to eliminate the need for anti roll bars.
Air suspension have become a common feature on flagships, full size
sedans and some off roading crossovers.
Air suspension is also sold as an aftermarket enhancement, it is sometimes called airbags in the aftermarket world as they
differ from the those found on high end vehicles. Aftermarket air suspension is used to get the hydraulics effect in car shows.
Unlike traditional spring suspension a damaged air suspension is unacceptable as any loss of compression would render it