If you’re after improved ride quality and a car that handles like a dream, then start with upgrades to the stock suspension. Most cars rely on a spring and shock combo to soak up road imperfections like potholes and speed bumps without rattling every bone in your body. While comfort is the main factor for everyday driving, stiffening up the suspension offers more control in corners and more stability at higher speeds. Coilovers have been the purist’s choice for driving fun, but are coming under increased pressure from bespoke air suspension setups riding on air springs. This is a layout being adopted by most luxury brands and paired with some advanced tech to offer a blend of unrivalled comfort and performance in one neat package.
Basics of Air Suspension
Air suspension revolves around the main components, pressurised suspension airbags, that take the place of traditional springs. The parts go by different names (air springs, bellows) but all perform the same function, to smooth out irregularities. A bonus is that like coil springs they’re progressive, so pressure can be adjusted to lift or lower the car as needed. This is done by inflating or deflating the bags to suit varying road conditions.
The tech isn’t new. It’s been used for decades in heavier commercial vehicles, but the benefits of air suspension are now slowly trickling down to everyday passenger cars, even those in entry trims. If you’ve been missing out, then aftermarket kits are readily available and can take the place of the stock suspension, with noticeable improvements in steering feel, braking and general handling.
Parts and How It Works
Recent tech based around ride height and pressure sensors, and advanced management systems that can change the pressure in car suspension air bags within a fraction of second, have contributed to the wider acceptance of air suspension. To understand how everything works, let’s break down the parts and what they do:
- Air bags – to cope with the weight of the vehicle and neutralise the effects of bad roads, heavy-duty vulcanised rubber able to cope with every high air pressure is used. Air bags are placed above each wheel, resemble two tyres stacked one atop the other (in convoluted types) and attach to the chassis via thick metal plates. They’re additionally reinforced in multiple points and have a rated recommended operating and burst pressure ( 480 and 600 psi, respectively), meaning each wheel and bag can comfortably handle several tons, or the whole weight of the vehicle. Double convoluted airbags are more compact in overall size. For utes, trucks and heavier vehicles look to tapered sleeve air bags. These can handle even higher weights and stresses and are usually seen on rear axles to balance uneven weight distribution.
- Shock absorbers – cheaper air suspension kits rely on the stock shocks, but for better calibration with bags, bespoke shocks tuned for vehicle weight perform better at containing rebound and compression rates in the air springs. These are standard kits orientated towards racing and performance applications.
- Air tanks and compressors – tanks store compressed air (at an average of 150 psi) that is drawn from the outside via an equally capable compressor. For serious uses, look to separates able to deal with higher air volumes and pressure. But is space in the boot is limited (this is where they’re usually located), choose tank and compressor combos.
- Air lines- these deliver air from tanks to one or all wheels. Cheaper air lines are made of rubber, but braided steel lines can take higher pressure and aren’t susceptible to leaks.
- Management systems and sensors – newer air suspension systems rely on height and air pressure sensors to inflate or deflate air bags. This is monitored and controlled by advanced electronic management systems. Manual types allow changing air pressure in each wheel separately. This is what you’d want in serious off-roading. Automated management systems work with other car systems, including radar-based cameras, to scan roads ahead, and automatically change pressure as needed. The setup is becoming more common in luxury vehicles, usually as standard kit.
Pros and Cons of Air Suspension
The system offers a range of advantages:
Lifting or Lowering Wheels
This is the main purpose of suspension airbags. As mentioned, wheels can be lifted separately or in combination. The process is quick and relocates compressed air to where it’s needed. SUVs and 4WDS for instance can benefit in lifting separate wheels for increased ground clearance. Similarly, passenger cars can be lifted for more comfort, or lowered to enable better handling, with a lower centre of gravity helping steering response and braking.
Flexibility
Air systems can be optioned and configured for different vehicles. What works for heavier cars may not work for smaller hatches or sedans. Air suspension is a common sight on rear axles in utes to prevent loss of traction and rear axle squat that compromises handling, braking and overall safety. They can also replace coilovers for faster track times, but the same setup can then transform the ride to deal with potholed backroads when getting home. An overlooked advantage is the versatility carowners have when going with tyre and wheel combos in bigger sizes, without impacting comfort levels.
More Forgiving
There’s less wear and tear to the suspension as a whole and to related parts including steering components and the tyres. The lower maintenance needs offset the relatively high purchase costs.
There are a few quibbles, though. As mentioned, fully automated systems on all four wheels can get pricey. And they can take a while to install. But once on you get to enjoy comfort levels unmatched in any other type of suspension. And the ability to change ride height on the fly. To ensure you get your money’s worth shop from reliable air suspension names. Some also do the installation.
