Citroën has released details of its innovative new suspension technology as part of what it calls the Citroën Advanced Comfort programme, which the company says will ultimately deliver unrivalled levels of on-road comfort for owners of all of its models.

The Citroën Advanced Comfort programme embraces not only the all-new progressive hydraulic cushion suspension system but also new seat technologies, improved body rigidity and acoustics to filter out road noise and vibrations.

Citroën is demonstrating these technologies via a prototype C4 Cactus known as the ‘Citroën Advanced Comfort Lab’, and the New C4 Picasso range, which goes on sale in the UK on 1 September, will be the first model to benefit from selected elements of the programme.

Built on the PSA Group’s EMP2 platform, the New C4 Picasso and Grand C4 Picasso have vertical rear shock absorbers and raised suspension arm joints to damp out imperfections in the road surface. The ergonomic design of the seats and the choice of materials also serve to help isolate occupants from road noise and vibrations. The front passenger can stretch out in an electric seat with a built-in leg rest. Finally, following studies into road noise, Citroën has increased acoustic comfort and vibration control by improving the damping of the front subframe and fitting a dual-material acoustic shim on the rear suspension.

The ‘Citroën Advanced Comfort Lab’ prototype C4 Cactus features three innovations that singularly, then collectively, reduce the vibrations felt by the passengers and, according to Citroën significantly improve driving comfort.

Citroën has filed more than thirty patents for the technologies implemented in this prototype, and they have all been developed to be applicable, from both a cost and production standpoint, to all the vehicles in the Citroën range.

Whereas a conventional suspension system is comprised of shock absorbers, springs and mechanical stops, Citroën’s new system adds two progressive hydraulic cushions – one for rebound and one for compression – at the top and bottom of each suspension unit. In this way, the suspension functions in two ways depending on the road surface:

In cases of slight compression and rebound, the springs and shock absorbers work together to control vertical movement without needing the hydraulic cushions. In cases of more significant compression and rebound, the springs and shock absorbers work together with the hydraulic cushions at the ends of the suspension travel. The new cushions gradually slow the movement, rather than having abrupt stops at the extremes of compression and rebound. Unlike a conventional mechanical stop, which absorbs the energy then partially returns it, the hydraulic cushion absorbs and dissipates the energy.

When the suspension has completed the damping process, the energy created by the irregular road surface is transferred to the vehicle body. The use of structural bonding techniques will significantly reduce this occurrence, thanks to increased overall stiffness.

Using an industrial process specific to Citroën, the structural parts of the vehicle are bonded together using a discontinuous line of adhesive. An electrical weld point is positioned wherever the line of adhesive is interrupted to ensure optimum rigidity during assembly.

This special bonding technique produces greater overall body rigidity, reduced weight and lower cost.

New seats provide a better combination of comfort and all-important posture support thanks to the introduction of different foam densities. In addition, Citroën took inspiration from the bedding industry to deliver memory seats that adapt to the body shape of each person. The seats regain their original shape from one passenger to the next.