How Air Suspension Works and What Its Advantages Are
Air suspension is becoming increasingly common in the automotive industry. Twenty years ago it was something unusual and rare; today it’s practically standard on all higher-end vehicle models.
All the so-called premium car brands — Mercedes, Audi, BMW, Porsche and others — build their high-end models with air suspension as standard, and even some lower-tier models come with it from the factory. A good example is certain estate/wagon models, where this type of suspension is a genuine convenience. When you load the vehicle, the rear doesn’t sag down to the ground, and at the same time the front doesn’t rise up too high. This is exactly where air suspension comes in — the system is pumped up by a compressor and the car levels itself back out.
For those who don’t know, air suspension replaces what’s known as coil spring suspension. These vehicles don’t have springs — in their place are air springs, which are inflated by a compressor. Every minute, various components — the compressor, level sensors and electronic control units — adjust the pressure in the individual air springs.
Comfort, Stability and Ride-Height Adjustment
The advantages of air suspension outweigh its drawbacks. Its biggest benefit is the comfort it offers the vehicle — it’s no coincidence that every Mercedes S-Class, Audi A8, VW Phaeton and similar model comes from the factory with air suspension as standard. Cars with this type of suspension handle small road imperfections far better. They ride softer, because compressing a spring is one thing, and compressing a bag filled with air is another. The air springs themselves consist of a rubber bellows clamped between two end plates, forming a bag that’s filled with air. The moment this bag develops any kind of hole — no matter how big or small — the air begins to escape and the vehicle leans to that side. That’s simply logical, since that air spring ends up empty while the other three stay full — which is exactly why the car settles to one side.
Another major advantage is that air suspension lets the vehicle change its ride height — higher or lower. This is a great convenience, especially here in Bulgaria, given the state of our roads. Almost every car with this system has a button that raises the vehicle by one level. Certain models from various brands — such as the Audi Allroad, the Mercedes ML with the off-road package, the Audi Q7 and others — offer more than one height-adjustment level. Air springs also allow — although it’s not recommended — a higher load capacity, since a spring-suspended vehicle squats down and changes its road stability when loaded, whereas air suspension compensates for that lean, keeping you steady on the road.