Air bagged suspension system in cars: Working, types & much more!

What is air suspension in cars?

An air suspension in cars is a unique type of suspension system that uses an electric compressor to pump air into different parts of the system. The role of an air bagged suspension is to manage the suitable drive height based on speed and terrain conditions.

Also called a pneumatic suspension system, air suspension plays an important part in delivering a constant smooth driving quality in a vehicle. Most of the high-end cars, passenger buses, trucks, etc., incorporate this type of suspension system. 

Air suspension system components

Usually, the components of air suspension include airbags, compressors, lines, valves, and solenoids. Every component assists in adjusting the driving height through the process of compressed air pumping. Let’s talk about each component in detail.

Airbags

An airbag is the most important component of the system that replaces the traditionally used coil springs. Depending on the manufacturer, the airbags can have different shapes. However, they are usually made of polyurethane and reinforced rubber to ensure toughness and structural integrity against sand and debris from the road.

There are three styles of bag shapes used in an air suspension system.

1. Tapered sleeve: This small cylindrical-shaped airbag can easily fit in tight areas. It allows easy placement and adjustable height of the system in a vehicle.

2. Rolling sleeve: The rolling sleeve airbag also offers adjustable control and driving height to the vehicle. Due to their small diameter, these airbags are used in light-duty vehicles with space limitations.

3. Double-convoluted bag: This type of airbag looks like an hourglass. The advantage of this type is the lateral flexibility it offers over the other two types.

Compressor

An air suspension system comes with a built-in compressor. It’s an electric pump that feeds air to the airbags. The compressor is usually placed either inside the trunk or on the vehicle's frame. Most compressors also contain a dryer, which is used to absorb the moisture out of the air before pumping it through the suspension system.

The workings of a compressor involve drawing the air from the atmosphere, using the dryer to remove the moisture, compressing the air and sending it to the bags through narrow air lines. While simpler systems rely only on the compressor for pressure management, advanced systems come with an additional component called an air tank for the same.

Lines

Lines or air lines carry the air from the compressor to the airbags. Mostly, they are made of polyurethane or rubber composition. But you can get them replaced with custom steel air lines. 

Valves

The system contains multiple air gateways called valves. They help to control the flow of air through different parts of the suspension system. 

Solenoids

These are essential in electronic suspension systems to vent and fill airbags. For required adjustments, the system commands solenoids to open/close accordingly to adjust the air quantity in every bag. 

How does air suspension work? 

The working of an air suspension system revolves around controlling the air pressure and cruising height. The operation of air bagged suspension systems is managed entirely by the onboard airbags, compressor, dryer, and valves.

The air is collected by the compressor from the environment. The dryer uses a moisture absorbent called a desiccant that dries the air before it gets pumped into the airbags through air lines. The pressure inside the airbags is managed in accordance with the required riding height. 

What are the types of air suspension systems?

Most air suspensions are pretty similar to each other. They differ with respect to the shape of their airbags and whether you can adjust them manually or electronically. Accordingly, there are four major types of air bagged suspension systems depending on their workings.

1. Convoluted air suspension system

These are air suspension systems with large rubber bellows. Such systems offer higher suspension capacity, making them suitable for heavy-load vehicles. 

2. Rolling lobe air suspension system

The rolling lobe suspension contains small-sized rubber airbags. These are usually used in smaller vehicles such as a sedan.

3. Coil spring bellows air suspension system

This is a unique type of air suspension which contains coil springs. The rubber airbags are installed inside the coil springs to provide better drive quality and higher stability. Unlike mechanical springs, these air springs adjust the driving height by controlling the air pressure inside the bags. 

Electronic air suspension system

An electronic air suspension system automatically controls the height of the vehicle. It uses undercarriage and speed sensors to adjust the suspension height.

Typically, an electronic air suspension offers the following five height adjustments.

1. Loading

2. Highway

3. Standard

4. Off-road

5. Off-road extended

The automatic system sets a suitable suspension height based on the vehicle speed. For instance, the “Highway” suspension setting usually works while driving at 80 km/h speed. However, off-road and off-road extended settings come into play at relatively lower speeds in rough road conditions.

Also, read: Car suspension: How does it work?

Advantages and disadvantages of the air suspension system

Like any other machinery, the air suspension system also has its unique advantages and disadvantages.

Advantages of air suspension system

Here are the advantages of air-bagged suspension systems.

1. Improved driving comfort

Cars with air suspension offer excellent driving comfort. The height adjustability allows a driver to obtain better control, especially in tough terrains. Passengers feel the minimal impact of the bumps on the road due to the compressed air bagged suspension. 

2. Less vibration and noise

Using air pressure adjustment, the suspension system experiences reduced vibration and harshness. The air pressure compensates for uneven surfaces, speed bumps, and potholes while driving without making much noise. It helps to have a pleasing quiet drive and increases the lifespan of the suspension system. 

3. Driving versatility

With an electronic air suspension system, you can smoothly drive a vehicle in different road conditions. The suspension works effortlessly on highways, mountain roads, and even rough off-road terrains. An automatic air suspension can reduce the ground clearance of its vehicle while driving at high speeds. On the contrary, it can also increase the vehicle height for off-roading and city drives, which makes cruising much easier.

4. Load versatility

The air suspension system lets you adjust the vehicle height based on the load as well. It ensures consistency of force distribution across the wheels to reduce the risk of roll-over accidents on turns.

It also reduces the risks of vibrations that may cause load shifting, breakage or damage while driving. As a result, carrying heavy loads becomes easier due to better control over the vehicle with air suspension. 

5. Fuel efficiency

Because of the adjustability of the suspension based on road type, you may experience an increase in the fuel efficiency of your vehicle. For instance, the lower drive height on highways reduces wind resistance and improves the vehicle’s aerodynamics. 

On the other hand, a higher drive height on city or mountain roads makes turns and slopes easier to cover, resulting in saving time and fuel in the process. 

Disadvantages of air suspension system

Here are the disadvantages you may face with an air suspension system.

1. High cost

The cost of buying an air spring suspension system is higher than a regular spring suspension. This is why only high-end or luxury cars come with in-built air suspensions. 

2. High maintenance

While you can rely on air suspension initially, it may require frequent repair work after long-duration or long-distance travel. You can’t avoid the repair needs, otherwise, it won’t be possible to keep the car stable while driving. Hence, maintenance cost is the necessary con you have to handle to avail all the benefits of air spring suspension.

3. Mechanical problems

The air suspensions also tend to face mechanical problems. Moisture and rust are common enemies that can damage the insides of the system. Moreover, the compressor may burn out if air springs start leaking air. Hence, regular check-ups and maintenance are necessary.

Air suspension cars in India

Due to their expensiveness, you will find mostly high-end cars with air suspension in India. Here is a list of cars with air suspension available in India as of May 2022.

Also, read:

1. Best suspension cars in India 2. Airbags in cars: Car airbag working, types, price and more 3. Electronic Stability Control (ESC) in cars and how it works 4. Nitrogen tyre inflation in cars: Advantages and disadvantages 5. Defogger in a car: How to defog car windows in the rain

Frequently asked questions

Here’s a set of common questions and their answers about air suspension systems in cars.

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