Citroën has announced that the replacement for its fantastic hydropneumatic suspension will be called Citroën Advanced Comfort. Because this would be the main heritage of its late suspension system: comfort. While that was also present, the hydropneumatic suspension also ensured very stable cars, something we have not seen the new system address. In fact, Citroën Advanced Comfort could be summed up as hydraulic bump-stops and seats with special foams.
The car chosen as a moving lab was the C4 Cactus, as the drawing above and the images in this article show.
Each damper has two hydraulic bump-stops: one for compression and the other for rebounds. One in each side of the shock absorber. In slight compression and rebound, they help the dampers and the springs to give the car the same “flying carpet” effect the hydropneumatic suspension gave the DS, the Xantia and many other models. But they do so only providing what Citroën calls a “greater freedom of articulation”. We are not very sure what it means.
When bumps and pothole start to really shake the car body, the hydraulic bump-stops gradually slow the movement. Citroën claims that this eliminates that bottoming sensation regular cars have. This would be the real test for the new suspension, since a hydropneumatic Citroën would just let you listen to the suspension working. These bump-stops would not make the dampers more expensive than regular ones, nor heavier.
Citroën says that another important element of Citroën Advanced Comfort is bonding the body together instead of welding it. That would improve stiffness in up to 20%, but we doubt PSA would do so with Citroën bodies and not with Peugeot models. In other words, if this bonding technique is ever applied to production vehicles, Peugeot cars will also use it.
The last step in the Citroën Advanced Comfort approach would be to use memory materials in the seats. The company claims to have developed these special seats with many different layers of polyurethane foam, viscoelastic or textured foam. The great challenge is to make them durable enough for a car. Mattresses and pillows have inspired the French carmaker, but they also get replaced more often than a car does.
The French website Autojournal has tested it and was pretty convinced by the performance of the C4 Cactus equipped with the technology. But, as they say in the article, a C5 with the hydropneumatic suspension would do the same. At a greater cost and with a much more difficult system to service. But was not this exactly what made Citroën models so special?
The fact is that scale is key to financial success and that complex technologies only pay off if they sell accordingly. This is what has killed the hydropneumatic suspension. And we will miss it a lot, even if the Citroën Advanced Comfort advances into mass production. Because it is clearly not a replacement. Just a way to try to make Citroën stand out of the ordinary cars it was unfortunately obliged to produce.