Citroen SM

Citroën SM at a glance

Development and production history

Citroën bought Maserati in 1968, and the SM was the first result. Robert Opron, Citroën's chief designer, styled the body in-house; Maserati's Giulio Alfieri designed a compact 90-degree V6 of aluminium, weighing about 140 kg, that sits behind the front axle. The car was launched at the Geneva Motor Show in March 1970, and French deliveries began that September.

Sales peaked straight away. Citroën built 868 cars in 1970 and 4,988 in 1971, then 4,036 in 1972 and 2,619 in 1973. North America took 1,250 cars in 1972 and 1,150 in 1973. After that the numbers collapsed: 294 cars in 1974 and 115 in 1975. English Wikipedia also states that the last 135 cars were built by Ligier, which does not fully agree with its own yearly figure for 1975.

Several things ended the SM. The 1973 oil crisis and the recession hurt sales of a fast, thirsty coupé, although English Wikipedia notes that many thirstier cars were launched at the same time. In the United States the SM could not meet the 5 mph bumper rule because of its height-adjustable suspension, and Citroën did not receive an exemption, so US sales ended after the 1974 model year. Of the 134 US-specification 1974 cars, none went to American buyers; they were sold in Japan. Citroën went bankrupt in 1974 and Peugeot took control. Peugeot sold Maserati in May 1975 and stopped the SM shortly afterwards.

Design and engineering

The SM uses the hydropneumatic self-levelling suspension of the DS, with four disc brakes and inboard discs at the front. Its steering, called DIRAVI, was fully powered and speed-sensitive, and the system was later used on the CX. The front carried six swivelling headlamps; they were illegal in the United States, where the SM had four exposed round sealed-beam lamps instead.

Citroën claimed a drag coefficient of 0.26 at launch, a figure later revised to 0.339. Michelin glass-fibre wheels were offered as an option. The coupé is 4,893 mm long on a 2,900 mm wheelbase, and its kerb weight is quoted at 1,450–1,520 kg, depending on the source and the version.

The Maserati V6 engine

Most SMs have a five-speed manual gearbox. A three-speed Borg-Warner automatic was offered in North America in 1972–1973 and in Europe in 1974–1975. Citroën gave a top speed of 220 km/h (137 mph), and independent tests reached 235 km/h (146 mph); 0–60 mph took 8.5 seconds. Our power converter gives the PS figures in kW and hp, and the power-to-weight calculator shows what 131 kW means for a car of about 1,450 kg.

Citroën SM specifications

Production by version and market

The version figures in English Wikipedia show how the SM was actually bought. Carburettor cars with the manual gearbox made up 7,133 of the 12,920 built, or about 55%. The fuel-injected 2.7 added 3,500 cars (27%). The 3.0-litre engine, built in smaller numbers, accounts for 1,612 cars, of which 1,012 had the automatic gearbox; together with the 675 automatic 2.7s, fewer than one SM in seven was an automatic.

The market split was just as uneven. North America took 1,250 cars in 1972 and 1,150 in 1973, so North America absorbed more than a third of the 6,655 SMs built in those two years. When US sales stopped after the 1974 model year, the SM lost its largest export market at the same moment as the oil crisis hit European demand. Output fell from 2,619 cars in 1973 to 294 in 1974.

Variants and derivatives

Henri Chapron built the rare coachbuilt SMs. Two four-door Présidentielle convertibles, stretched to 5.60 m, served French presidents from Georges Pompidou to Jacques Chirac; they were retired after 37 years with about 25,000 km on the clock. Chapron also made five Mylord convertibles and seven Opéra saloons. In February 2014 a Mylord sold at auction for €548,320.

The engine lived on at Maserati. The Quattroporte II, a four-door car on SM mechanicals, entered production in 1976, and 12 were built by 1978. Citroën named no direct successor, but the CX of 1974 carried forward much of the SM's technology, including the DIRAVI steering.

Rallying and awards

The SM won its first competitive outing, the 1971 Rallye du Maroc. It finished third in the 1971 European Car of the Year contest and won Motor Trend's Car of the Year award for 1972. More of Citroën's story is in our history of Citroën, and the story of its Italian engine partner is in the history of Maserati.

Photo gallery