Carole Nash
Content Writer
Published: 1st February 2019

Within the car industry there are certain motors that have an unmatched ride quality. The ‘magic carpet ride’ is the feeling of absolute comfort of driving a car that’s travelling at a high speed. Citroen cars have a history of providing this kind of ride and it’s because of a clever design called the hydropneumatic suspension system. We’re taking a closer look at how the system worked.

What is a hydropneumatic suspension system?

The system is different to other car suspensions because it bypasses the steel springs found in most vehicles. The wheels are connected to a steel sphere containing nitrogen, which can be compressed and hydraulic fluid, which can’t be compressed. Also, the sphere houses a rubber membrane that separates the fluid and nitrogen.

Older versions of the system relied on an engine-driven pump to fill the bottom of the sphere with pressurised fluid. When a car drove over a bump, the fluid compressed the nitrogen through pushing the membrane up and it created a damping effect.

Getting the magic carpet ride

Hydropneumatic suspension appeared for the first time in the 1954 Citroen Traction Avant. It served as the testing ground for the DS, which incorporated a more advanced version of the system. It eliminated body roll, which translated to hard cornering as well.

The system proved to be beneficial in racing because the DS could drive fast over uneven ground. The racing experience was comfortable. People quickly saw the DS’ potential, with the car winning several races, like the 1959 Monte-Carlo Rally.

Despite the success of hydropneumatic suspension it cost Citroen a lot to develop. This led Citroen to introduce stripped back models like the ID 19. The system was vital in 1962 when the French president Charles de Gaulle used a DS as his official car. After he granted independence to Algeria, twelve gunman opened fire on de Gaulle during a parade. Only a handful of bullets hit the DS and the driver was able to get the president to safety. This came down to the smoothness of the hydropneumatic suspension.

The ride quality of Citroens were so impressive that Rolls-Royce licensed the hydropneumatic system. It was installed in the 1965 Silver Shadow. Over time, Citroen looked to offset the cost of making the system, so they developed cars that were meant to be practical and cost-effective.

There’s no denying that the hydropneumatic suspension system is one of the most impressive car systems of all time.

Image credit: Autocar.com