Citroën to celebrate 50 years of the SM at Retromobile

Like the DS it was based upon, the Citroën SM was a technological masterpiece, way ahead of its time. Its avant-garde design made it an instant future classic and so it comes as no surprise that it will form the centerpiece at Citroën's stand at Retromobile this year.

The iconic Citroën DS, launched to a stunned world in 1955, was already a legend when work started on "Project S", which was to become the SM in the '60s. The plan was to build on the DS's technological lead and create a new sports vehicle that would become the brand's flagship. The lead engineer, Jacques Né, initially had plans to go racing at Le Mans, but managing director Pierre Bercot had other ideas - the SM was to be a prestige, luxury car.

To save costs, it shared a lot of components with the DS, and was even built on the same lines at the Quai de Javel, in Paris. The design team was headed by the legendary Robert Opron, and included Jean Giret and Jacques Charreton. With Maserati in the Citroën fold, an Italian workshop launched a study into a small, modern, V6... After the death of Flaminio Bertoni, the SM was to be the first of the Opron-era cars.

When the SM was launched at the 1970 Geneva Motor Show, it once again stunned the world, just as the DS did 15 years earlier. Its styling was dramatic, and it was powered by a Maserati 90-degree V6 engine with two overhead camshafts per cylinder bank. With an engine capacity of 2.7L, the engine was light and compact, and the alloy block was initially fed by three dual-body Weber carburettors to produce 170 hp (127kW) at 5 500 rpm. Later on the engine received Bosch fuel injection and power went up to 133kW.

Like the DS, the SM made use of a central hydraulic system and the green LHM fluid fed and supported many of the main functions, such as the suspension, braking, steering and vertical adjustment of the headlights. One notable difference to the DS was the fitment of a tie-rod front axle.

In fact, steering was a main focus point for the SM. Called DIRAVI the "memory-assisted" steering boasted the special feature of "hardening" with speed, thanks to a hydraulic governor mounted at the end of the gearbox. This system gave the SM light steering in town, but more direct, meatier steering at speed.

The car was (and still is) a favourite of the world's rich and famous. Leonid Brezhnev, the Shah of Iran, Haile Selassie, Burt Reynolds, Johan Cruyff, Bernard Pivot and Line Renaud are some of the famous owners. More recently, Jay Leno still owns an SM, and James Bond, Daniel Craig, admits to it being one of his dream cars.

At the time of its launch the SM cost the princely sum of 46 000 French Francs, the equivalent of 46 400 Euros today. 12 920 cars were produced between 1970 and 1975. Henri Chapron Bodywork built 7 Mylords (convertibles), two Elysees (convertibles for official ceremonies) and 7 Operas (four doors). Hueliez designed 2 SM Espaces.