1972 Citroen SM

The 'Project S' began in 1961 as Citroen's desire to develop a sports variant of the revolutionary DS. Many running concept vehicles were developed with upmarket features and increasingly complex technology to differentiate the 'sports' project from the popular DS.

The SM (Série Maserati) was a combination of Citroen's advanced chassis technology and Maserati engine knowledge. It had DS-style hydro-pneumatic suspension, power-assisted, all-around load-sensitive disc brakes, and fully-powered, self-centering steering that allowed the car to be set up with zero casters, which kept the tires in full contact with the road at all times. Maserati had been acquired by Citroen in 1968, primarily to gain the engine technology for its new top-of-the-range Gran Turismo Coupe. Maserati removed two cylinders off its Indy four-cam 90-degree V8 to create the required V-6. The exterior style was an aerodynamic fastback body, with plenty of glass, unadorned flanks, and skirts over the rear wheels. There was an asymmetric air intake on the bonnet and hydraulically adjustable and swiveling headlamps under curved heated glass. Styling was penned by in-house chief designer Robert Opron and had a very impressive drag coefficient of 0.26.

The SM's class-leading drag coefficient enabled it to reach 140 mph, making it the fastest front-wheel-drive car ever at that time. The Citroen SM made its debut at the Geneva Motor Show in March of 1970. It went on sale in France in September of that year in left-hand drive only, although right-hand drive conversions were later offered in the UK and Australia.

The Maserati built V-6 engine displaced 2,670cc, but with the help of three Weber downdraft carburetors, it offered plenty of performance. In 1973, the displacement grew to 2,965cc, and for the smog-equipped U.S. cars, it offered 190 horsepower at 6,250 RPM. Available with a five-speed automatic or manual transmission, it had disc brakes on all four corners.

The SM introduced a new type of variable-assist power steering dubbed DIRAVI.

by Daniel Vaughan | Oct 2019