Everything You Need to Know about Air Suspension

Ever hit a pothole at speed? Well, you know the feeling. Now, think of doing the same with worn or no suspension. There’s not only the kick in the back, and the eventual whiplash, but the car can literally fly off the road. The role of a car’s suspension is not only to smoothen out imperfections in the road, but also to keep the car planted. It absorbs the weight of the vehicle, passengers and luggage without changing the ride or handling. Damaged struts or shocks won’t go far in providing either passenger comfort or safety. The resulting vibrations also affect every part of the car, and lead to premature wear and costly repairs.

There are different ways carmakers tend to absorb those nasty bumps on the roads, while also providing for better control and handling. Suspension setups vary from vehicle to vehicle. Some will be aligned to provide more comfort, going on the cushy side, while others will be more attuned to a sportier, stiffer feel that also lets you throw the car about in almost any way. The best of both worlds is provided with an air suspension car system, giving the most feedback and control in bends and the best possible levels of comfort.

What is Air Suspension?

Air suspension swaps out the traditional layout of coil or leaf springs for pressurised rubber bellows, known as airbags (not to be confused with internal airbags) or air springs. These are fed with air by an onboard compressor and air tank. The air flows through from the tank to the bellows in a network of air pipes. To keep the air dry, air suspension also needs an air-drying canister. The whole system is controlled by an onboard computer with data from air pressure sensors. The computer is responsible for monitoring the air pressure in the bellows and provides the right amount of air when needed.

Reinforced bellows can be positioned at all four wheels, or only at the rear axle. The role of air suspension is to allow drivers to adjust the ride height with a simple flick of a knob. Most air suspension car systems include multiple levels of adjustment to change the ride quality and the car’s ground clearance according to the road conditions and the weight of the vehicle when loaded. The system is featured in many high-end luxury and sports cars either as standard or optional equipment. It can also be fitted to cars with regular suspension setups.

The idea is nothing new, and a precursor to the concept of cars ‘riding on air’ dates back more than a century, when vehicles were just hitting the roads. Pneumatic suspension, using springs with pressurised hydraulic liquid, first made its way in production cars in the 1950s. Thank Citroen and French eccentricity for that. True air suspension systems though came to light during the Second World War, first in aircraft then heavy trucks. The first car to have the system as we know it today was the 1993 Range Rover.

The Purpose of Air Suspension

The goal of air suspension is to smoothen out any imperfections on the road. In addition, it provides for a comfortable ride, but the handling is maintained even with the vehicle sitting higher than usual. It allows drivers to maintain more speed when cornering, while also levelling the vehicle on the flats. To this end, air suspension features in many sports cars. Another common application is in heavier vehicles. Many trucks have replaced springs and coils with reinforced air bellows to better handle the added weight.

Benefits of Air Suspension

The most obvious reason to install air suspension is that the car’s ground clearance and height can be easily adjusted within a matter of seconds. You can lower or lift the car to any height that you find suitable. And this in itself is useful in many driving situations.

Consider, for instance, the benefit when off-roading. The first car to have air suspension was after all a luxury 4WD. Being able to lift the chassis to go over higher obstacles, even while driving is an advantage not all 4WDs have. Those without that option run the risk of damage to the underbody or getting stuck.

Lowering the suspension also has its benefits, especially for vehicles sitting high as most utes and 4WDs. A lower ride height, means there’s less drag, so overall consumption is reduced.

In terms of handling, air suspension car systems better soak up bumps than traditional setups. There’ll be fewer vibrations and noise seeping in the cabin, which also translates to a quiet, comfy ride. In addition, reducing vibrations also reduces wear. The suspension parts don’t suffer from the high mechanical stresses of bending steel. Tyres also last longer. High-end cars pair air suspension with predictive tech to constantly scan the road ahead to adjust the height of the car in real-time according to the road conditions.

For utes, adding air suspension to the rear axles means the car maintains a more natural profile at all times. It won’t look jacked up when the tray or tub is empty. Nor will it be sagging when fully loaded and the front wheels struggling for traction. Minor niggles are the price and cost of replacing defective parts. But for all the benefits air suspension offers, these are negligible at most.