Last year, it was revealed that Citroen would retire its iconic hydropneumatic suspension design when the current C5 range ends. Now, the company so well-known for its comfort-focussed suspension, has revealed the first details of its next-generation system.
Showcased with a C4 Cactus-based concept car, Citroen's Advanced Comfort technologies are incorporated under the skin, in the body and in the cabin.
In describing the new system, Citroen first outlines three stages of the effect when any car drives over a bump or dip: 1) The suspension takes action, 2) The vibrations are transferred to the body, and 3) The vibrations are felt by the passengers through the seats.
According to Citroen, three new technologies featured in the Advanced Comfort concept address each stage of vibration transmission, to help reduce the amount of feedback felt by passengers, in turn improving driving comfort.
First is the suspension, which takes the standard spring, shock absorber and mechanical stop setup, and updates it to include two hydraulic stops - one for rebound and one for compression - on either side.
The progressive stops act as cushions at each end of the suspension, functioning in two stages depending on the amount of compression input.
Under slight compression and rebound, these stops aren’t needed to control vertical movement, however they allow greater freedom of articulation to deliver what Citroen claims is a “flying carpet” effect - giving the impression that the vehicle is gliding over imperfections and undulations.
Meanwhile, when the going gets a little tougher, the shock absorber and the spring work together with the hydraulic cushions at each end of travel - compression and rebound. The car maker says the hydraulic stops help to gradually slow movement and avoid jarring by dissipating the force, rather than absorbing and partially returning it the way a conventional mechanical stop setup would.
The second Advanced Comfort technology is structural body bonding, which involves fusing various parts of the vehicle’s structure together using a discontinuous line of adhesive, along with electrical welding wherever the line of adhesive is interrupted.
The bonding technique is said to make the body stiffer - on average about 20 per cent - which helps to isolate it from external vibrations, while also keeping weight and costs down.
Finally, the seats in the special C4 Cactus combine the conventional look of a car seat with the comfort of 'memory foam' mattresses and pillows found in bedding.
The new seats are designed to support the passenger in extreme comfort when seated, while also helping to dampen out vibrations normally felt through the pews when driving. Adding to passenger comfort is the memory-shape foam which conforms to any passenger’s shape.
While the previous hydropneumatic suspension system was reserved for higher-end models in Citroen’s line-up, the company says its new Advanced Comfort technologies have been developed to be applicable across all vehicles in its range.
However, there has been no confirmation as to when we will see the new techniques on production models, nor which models will be first to feature them. For now, the concept provides at least an insight into what Citroen has planned for its future models.