A self-leveling suspension is a type of automobile suspension that uses air bags and air compressors or pumps to maintain a level attitude when the vehicle is loaded down. Sensors, typically electronic, are positioned on the vehicle's chassis in critical areas to determine the attitude of the vehicle. When a sensor indicates an unlevel attitude in a specific area of the vehicle's chassis, such as the rear section of the chassis, the self-leveling suspension is activated to raise or lower the air bags in that area of the chassis. The air compressors or air pumps will activate to pump air into these air bags to raise the chassis to a level height or bleed air off of the self-leveling suspension to lower the chassis to a level height with the rest of the chassis, both front and rear as well as left and right.
Offered mainly on high-performance sports cars as well as utility vehicles, the self-leveling suspension is a critical factor in creating a well-handling vehicle. By placing weight equally on the front and rear axles, the self-leveling suspension aids the vehicle in proper steering and braking proportioning to create a stable driving platform for the driver. The self-leveling suspension systems used on factory-equipped vehicles works so well in this area that the systems are not legal on most forms of racing vehicle as they are considered an unfair advantage.
While the air bag is typically the component of choice in the modern self-leveling suspension, early versions of the system utilized air-operated shocks to achieve the adjustability of the suspension. The shocks worked well as leveling components, however, they also provided a stiff and harsh ride when subjected to full-load capacity. The air-filled shock lost most of its absorption capabilities and acted more like a solid ram, failing to provide a soft and cushioned ride for the vehicle's passengers.
The air bag system used on the modern self-leveling suspension is derived from the air bag suspension system that has been used on long-haul semi-trucks for years. The system has been proven to be durable and long-lasting as well as effective and easy to maintain. A small on-board air compressor easily makes inflation adjustments which are controlled by the vehicle's computer system that monitors the vehicle's ride height several hundred times per second. Often the adjustment of ride height is undetected by the vehicle's passengers as the self-leveling suspension corrects itself while the vehicle is in motion.
