Citroën ID 19 Saloon- 1959

The Citroën D series was the sensation of the 1955 Paris Auto Show. With its streamlined silhouette and its hydro-pneumatic suspension (no springs), this car had many features that were ahead of its time. The D series was produced as both the ID and DS – the ID series had a manual transmission and cloth interior, and the more luxurious DS series had leather seats and a shift lever but no clutch (called Citromatic).

The D series rides on four struts (“spheres”) that are filled with a hydraulic fluid on one side of a diaphragm, and nitrogen gas under high pressure on the other side. When the car is started, the hydraulic pump pressurizes the system and the car is raised on the adjustable suspension. A lever in the left footwell allows one to select different ride heights. This same system also supplies operating pressure to the power brakes and power steering.

Sixty years after its introduction, the D Series cars still appear near the top of virtually every “most beautiful car” and “most influential auto design” list.