I believe the Citroen DS is one of France's greatest contributions to the modern world, up there with the metric system.
The reason behind such a seemingly hyperbolic statement is simple: The DS is the single greatest evolutionary leap in Automobile history that's been made between the end of WW2 and the launch of the Tesla Model S in the Third Millennium.
The DS looks, drives, and was made like no other car before or since.
Its development lasted the best part of a decade, during which the Bureau D'Etudes Citroen, under the direction of Andrè Lefebvre, pretty much reinvented the automobile one sub-system at a time.
The Italian artist Flaminio Bertoni, who had designed the Traction Avant 20 years earlier, drew inspiration for the DS from aquatic creatures: sleek shapes that silently glide through the water. The DS has no imposing front grille, the only badge it wears is at the back, yet there's no mistaking it for anything else. Those lovingly sculpted panels carry no loads, as the car's structure hides beneath them. Its design was optimized for best weight distribution. Thick, sturdy steel box sections down low gradually became thinner and lighter as they reached the roof, which is a glass fiber panel screwed and bonded into place. The thin pillars, frameless side windows, and wraparound front and rear screens give drivers and passengers a nearly unobstructed view of their surroundings while enjoying an experience unlike any other car before.
This type of body construction was meant to facilitate styling updates, yet the DS's appearance hardly changed over nearly two decades on the market. The four headlights front end, which debuted in 1967, could be considered the best restyling ever made in automobile history, as it brought the DS bang up to date and looking perhaps better than ever.
the DS remained a unique automobile, its influence over the wider automobile industry somewhat limited, as the pursuit of beauty and engineering ideals hardly pays the bills
The DS's engine-driven high-pressure hydraulic system assisted the steering, engaged and disengaged the clutch, and powered the brakes, activated by a mushroom-like pedal that responds to the force applied to it, rather than pedal travel.
But the key function of the high-pressure hydraulics was, of course, the self-leveling, height-adjustable hydropneumatic suspension.
At the heart of the system are the so-called spheres, five on the DS: one per wheel acting as suspension elements and one as the main accumulator. The spheres are hollow steel balls opened at the bottom, with a rubber membrane in the middle creating two chambers. The top one filled with nitrogen at high pressure; the bottom one is connected to the car's hydraulic system, whose high-pressure pump is powered by the car's engine.
The suspension works by means of a piston forcing the LHM oil into the sphere, compressing the nitrogen in the upper part of the sphere, while the damping is achieved through a two-way valve placed at the bottom of it.
Ride height correction is achieved by height corrector valves front and rear. As the rear brakes are actuated by the rear suspension circuit, the brake pressure is automatically adjusted to vehicle load.
The result was a level of comfort and safety miles ahead of anything available in 1955, and arguably still unmatched by April 1975, when production of the DS stopped for good.
Yet the DS remained a unique automobile, its influence over the wider automobile industry somewhat limited, as the pursuit of beauty and engineering ideals hardly pays the bills. The DS was a labor-intensive car to build, and bringing it to market required the costly development of proprietary technology.
For the operation to be profitable, Citroën should have built at least 500 cars per day, but that's a figure it hardly achieved even at the model's peak in the late '60s. Properly replacing the DS would prove impossible even for Citroen itself, which lost its independence in 1974. The last car it developed on its own, the CX, enjoyed considerable market success, but it did not represent the technological and design leap the DS had been two decades earlier.
Personally, I've fallen in love with the DS when I was little. My dad owned a BX, and the local Citroen dealer had a few old DS lying around. Despite those poor old cars' miserable conditions, their shape captivated my imagination, fostering my enduring love for automobile design and engineering.