What Is the Difference Between Air Suspension and Standard Springs?


AudiWe regularly get asked the questions “what is air suspension” and “how to install air suspension parts” from our customers at CarAirsprings. Another question commonly asked is: “what is the difference between air suspension and coil spring suspension?”, or can we compare “air spring vs coil spring?”

Thankfully Girlracer shares our concern surrounding this issue and has offered us a place to share our thoughts. The purpose of this article is to briefly outline air suspension pros and cons; compare them to traditional coil spring suspension and the option of coilovers; to outline the benefits and disadvantages of both.

What is Coil Spring Suspension?
Coil springs are a strong steel spiralled rod that stretches and compressed with increasing or decreasing pressure from the wheel. It is usually closely aligned next to the damper/shock absorber. The shock absorber contains a piston that passes back-and-forth with the movement of the wheel.

An alternative to this system is the “coilover spring”, which is a very popular form of suspension in modern-day vehicles. The set-up of this suspension is a coiled spring wrapped around a shock absorber and usually comes as a single installed unit. Coilovers provide damping for the vehicle and can be adjusted by altering between different spring rates.

What is Air Suspension?
Air suspension is a form of suspension that is motorised by an air compressor that is electrically powered or powered by the vehicle’s engine. The compressor powers the air suspension bellows, which can be controlled by either an electrical or self-levelling system. Depending on the vehicle, the air suspension bags are controlled directly from the compressor or they are attached to a shock absorber for added impact-minimisation.
There are custom suspensions that mechanics can install, changing from their standard coil suspension set-up, and there are many companies changing to air suspension altogether. Some of the companies to do so are Mercedes, Land Rover, BMW, Audi, Volkswagen, Porsche, Ford, Lexus, and Subaru; to name but a few.

However, this still leaves us with the questions: Air suspension vs coilovers; air suspension vs springs?

Air Suspension vs Spring Suspension
Some of the notable advantages of coilovers are that they allow for easy aftermarket replacement and allow drivers to get very specific coilovers as per their requirements. However, because of the spring’s placement, it exacerbates the wear-and-tear of the shock, the bushing and is generally more expensive than traditional springs and shocks, and also air suspension alternatives.

Similarly, air suspension offers all of the benefits that coilovers do, as they are widely available and can be easily installed by your local mechanic. Where air suspension is superior is that it does not place the same burden on the vehicle’s bushing and provides a far smoother and pleasant drive for the end-user. Cars appear to easily move over bumps in the road without much impact and cars have an improved towing ability as spring suspension tends to have a greater impact on the vehicle.

However, as with most things, there are air suspension pros and cons, as well. Airbags can malfunction, airlines fail, compression failure or air-line failure; so they are not faultless.

There are advantages and disadvantages of both forms of suspension, so it all depends on the needs of the driver as to what option is preferable. Air suspension provides a smoother driving experience, handling bumps quite effortlessly. Whereas, coil springs and coilovers are generally less expensive than air suspension replacements.

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