Air Suspension: Everything You Need to Know

Until recently, most cars were fitted with mechanical springs and shocks to absorb road imperfections and offer a tolerable ride. That has all changed, especially at the higher end of the market, with luxury brands pushing innovative suspension setups that don’t compromise on comfort or performance. Air suspension in different guises and names has become standard gear on higher trims but is slowly and surely making its way into the mainstream. Its popularity is based on adjusting the ride height in the air springs for changing driving and road conditions. This can be done within seconds and improves handling, cornering and braking performance, while the car glides over potholes and bumps with ease. 

Basics of Air Suspension and How it Works

The whole setup consists of quite a few air suspension system components, with reinforced air bellows at their centre. These take the place of conventional coil springs, and like coils are progressive, so can be adjusted to differing air pressures and essentially lower or lift the car as needed. Air to the bellows is supplied from reservoirs and tanks through plumbing components, while complex management systems work out how much air pressure is needed in each air bag to level out the car. 

Air suspension has been a standard component of heavy vehicles like trucks and buses where they deal with changes to weight distribution and increasing stability. Recent technological advancements, like incorporating ride height and pressure sensors, and higher availability have meant lower prices and setups well-suited to passenger vehicles. 

The Parts

While at first glance complex, air suspension has been perfected to offer numerous benefits for a variety of vehicles. This is all down to parts that are tailored to the specifics of each vehicle: The major components include: 

• Air bags – or air bellows/springs – are made of heavy-duty vulcanised rubber able to withstand very high pressures. Bags are placed above each wheel (or at the rear wheels in utes) and attached to the chassis by plates. They come in different types. Most common in cars are double-convoluted types, resembling two tyres stacked one atop the other. and provide high loading rates and shorter strokes. They’re mainly used in cars and do a fine job at varying speeds. Trucks and heavier vehicles often deploy roller or tapered air bags, usually in a three-bag configuration. Compared to air bags in cars, they are narrower and higher and are more about evenly spreading loads on the rear axle. 
• Shocks – More costly air suspension kits will also have separate shocks calibrated for the weight of each vehicle. This setup is much like coilovers in terms of outright performance, allowing for more control in compression and rebound rates, and increasing ride quality and comfort. Standard kits make do with the stock shocks. 
• Tanks and Compressors – compressors draw outside air, pressurise it and this is then transferred to the tanks, ready for use. Some kits have compressors and tanks as a single unit to save space. 
• Air lines – getting air from the tanks to the bellows is done with air lines. Lower-cost options are made of reinforced rubber, but if you’re dealing with heavier and bigger cars, braided steel lines are the way to go. Controlling the amount of air that gets into the air bags is the task of solenoids or valves. 
• Sensors and Management Systems – newer cars have both pressure and ride height sensors that monitor vehicle height and the pressure in the bellows in real-time. This data is relayed and assessed by complex management systems that open or close valves to inflate or deflate the air bags. Manual systems are less expensive and often have dash-mounted controls. Luxury cars do this on your behalf, with everything being automated, and utilising additional tech like front-facing cameras that scan the road ahead to allow for adjustments beforehand. This is how cars simply glide over any road imperfections. 

Why Consider Air Suspension?

If luxury car and SUV brands are making the shift to air suspension system components in all their vehicles, it’s because of the long list of benefits they provide. Lowering or lifting the vehicle with a simple flick of a switch (or on its own) proves handy in dozens of cases. Lower ride height stabilises vehicles when cornering, with less body sway and more control through the steering wheel. There’s more traction through the tyres, a more aero stance and more controlled braking, without excessive diving at the front or squat at the rear axle. In short, air suspension substantially improves performance and handling.

Conversely, lifting the car also has its pros. Air bellows have more leeway when traversing rougher roads and absorbing imperfections than standard coils. Moreover, the ability to lift the vehicle at each wheel is something you’ll appreciate when off-roading to get out of tight spots, particularly in 4WDs, and this trumps any lift kit currently sold. For utes and trucks, air ride suspension helps with traction at the rear axle with tubs and trays loaded to the brim, as well as when towing heavier trailers and caravans.

In this respect, air suspension is also more forgiving on related vehicle parts like control arms, and steering assemblies, but especially tyres, leading to lower wear. With lower maintenance costs for replacement parts, you’ll be recouping the initial cost of all the parts in no time, while enjoying maximum comfort, superior handling and outright convenience.