ir suspension systems essentially replace a vehicle's coil springs with air springs. The air springs are simply tough rubber and plastic bags inflated to a certain pressure and height to mimic the coil springs. But the similarities end there. By adding in an on-board air compressor, sensors and electronic controls, today's air suspension systems provide several advantages over all-metal, conventional springs, including near-instant tuning, and the ability to adapt handling to different situations and vary load capability. Whether the system is manual or electronic, or installed by a weekend mechanic or a seasoned tech, air suspension can lower a car to improve its street cred, even out a heavy payload, or simply improve the ride of a vintage Detroit metal street monster.

In 1901 an American, William W. Humphreys, patented an idea - a 'Pneumatic Spring for Vehicles'.[1] The design consisted of a left and right air spring longitudinally channeled nearly the length of the vehicle. The channels were con-caved to receive two long pneumatic cushions. Each one was closed at one end and provided with an air-valve at the other end.[2]
From 1920, Frenchman George Messier provided aftermarket pneumatic suspension systems.[3] His own 1922-1930 Messier automobiles featured a suspension "to hold the car aloft on four gas bubbles."[4] & auto.howstuffworks