Ride goes up, ride goes down—but how does air suspension actually work?

Have you seen a car so close to the ground that you wonder how the driver can operate their vehicle? Or maybe even a car hissing to the ground? They are likely using air suspension, which is commonly referred to as bagged suspension. Highly different from what comes on passenger vehicles from the factory, bagged vehicles can adjust their ride height on the fly.

From the compressor to the management system, here's how air suspension works.

Besides making cool noises, air suspension setups are more practical than you would presume. Typically, the main reason for air suspension setups is to obtain the ability to raise or lower your car as you please. In turn, you achieve a lower center of gravity all while retaining the smoothness of a stock vehicle, making them popular among car enthusiasts.

Air suspension is also popular on towing vehicles, as it is primarily used to counteract the tongue weight of the trailer. This gives you more control and stability when driving at higher speeds. In addition, additional air suspension components reduce the stress on your vehicle's existing suspension components, as they weren't intended for the additional weight. Each vehicle has a GVWR (gross vehicle weight rating), which is the vehicle's total weight and capable payload.

Improper balance in your vehicle can drastically decrease your vehicle's performance and towing capacity. This is not to suggest that air suspension assistance will increase towing capacity or payload but rather increase safety and stability. Modern vehicles combat this problem by automatically adjusting the suspension, such as Tesla's Model X.

Air suspension is also found on semi-trucks, ambulances, buses, and numerous other large vehicles and serves more than one purpose.

There are four components in an air suspension setup: an air tank, a compressor, some struts, and an air management system. Traditional MacPherson-Style struts are independent of one another, constructed of their strut and spring, whereas bagged suspension setups are part of a central system. The air management system is the brain of the operations, requesting or releasing air as each strut needs.

The air tank is responsible for containing the air pressure created by the compressor. With commands from the air management system, the compressor will either kick on or release air from the tank to the strut to adjust the vehicle's ride height. Commonly used on lowered vehicles, this ultimately eliminates the challenge of going over speed bumps. Similarly, on towing vehicles, air suspension components are placed between the existing suspension components to compensate for the additional weight of the trailer.

Like most car modifications, air suspension is not always sunshine and rainbows. The pros and cons of owning a bagged vehicle are drastic, but ultimately for the driver to decide. If bagged suspension setups didn't offer enough desirable amenities, people wouldn't go through the hassle of installing such complex suspension setups. All things considered, here are some of the benefits and drawbacks of bagged vehicles.

The most desirable feature of a bagged vehicle is the ability to raise and lower your car. You can achieve an incredibly low stance out of your vehicle and evade large speed bumps, all while retaining the smoothness of a factory suspension. While this doesn't seem like much, most lowering options sacrifice the smoothness of your stock suspension. With the ability to lower your car and retain smoothness, you can get the best of both worlds.

In addition, there are also more performance benefits than meets the eye. The lower center of gravity results in better handling, increased stability, and lower wind resistance, which generally results in a seriously sporty ride.

Furthermore, towing vehicles also reap benefits when air suspension is added to the vehicle, as it helps with the additional tongue weight on the car. An evenly balanced vehicle results in less sway and more stability while traveling at higher speeds. This ultimately increases safety and ride quality when towing heaving weight.

While bagged suspension setups may pique your interest, they may hinder your vehicle's reliability. Air suspension setups are far more complex than MacPherson-style struts, making the added components increase the likelihood of failure or malfunction.

Also, far from cheap, air suspension setups typically run well over double or triple what traditional MacPherson-style struts could ever cost you. From management systems to the actual bags on the suspension, these various parts and fittings will run you well over a few thousand dollars.

Additionally, air lines may leak or get pinched by their surroundings, potentially making bagged vehicles more of a nuisance than a luxury. Air lines can also collect condensation in colder climates, making bagged vehicles useless. Since water expands in its solid state, this makes it potentially dangerous for air management systems. Water traps and coolant-filled tanks can mediate this issue but ultimately add to your bill and list of preventative car maintenance.

Lastly, bagged suspension generates compressor noise. The air compressor turns off when it reaches its threshold and kicks on when needed. It is inevitable in an air suspension setup but doesn't necessarily justify the extra noise generated from the rear of your vehicle.

Air suspension setups are rather versatile since you can change your vehicle's ride height as you please. Bagged suspension setups prove most viable for those with lower vehicles, allowing you to go over the largest bumps. Its versatility even applies to towing vehicles and semi-trucks, compensating for additional payloads as necessary.

Despite the additional suspension components and added cost, the perks of air suspension allow you to do the extraordinary. Whether you want to tow extra weight or appear low to the ground, the help of air suspension can help you achieve what you're looking for.

Based on the East Coast, Joshua Ko is an automotive writer and European Car Enthusiast. Graduate with a bachelor's degree in English from Pennsylvania State University that spends most of his time outdoors, writing, or in the garage.

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