Citroën SM

Citroën SM
Citroën SM
Overview
Manufacturer	Citroën
Production	1970-1975
Designer	Robert Opron
Body and chassis
Class	Grand tourer
Body style	2-door coupé
Related	Citroën DS; Maserati Merak; Maserati Quattroporte II; Citroën CX
Powertrain
Engine	2.7 L V6; 3.0 L V6
Dimensions
Length	489.3 cm
Width	183.6 cm
Height	132.4 cm
Curb weight	1460 kg (carburetted version); 1520 kg (fuel-injection version)

The Citroën SM was a high performance coupé produced by the French manufacturer Citroën between 1970 and 1975. The SM placed third in the 1971 European Car of the Year contest, trailing its stablemate Citroën GS, and won the 1972 Motor Trend Car of the Year award in the US in 1972.

History

In 1961, Citroën began work on 'Project S' - a sports variant of the revolutionary Citroën DS. As was customary for the firm, many running concept vehicles were developed, increasingly complex and upmarket from the DS - eventually becoming a halo vehicle for the brand. Citroën purchased Maserati in 1968 with the intention of harnessing Maserati's high performance engine technology to produce a true Gran Turismo car, combining the sophisticated Citroën suspension with a Maserati V6 engine.

The result was the Citroën SM (Sport Maserati), first shown at the Geneva Motor Show in March1970. It finally went on sale in France in September of that year. All produced were left-hand-drive, although some RHD conversions were done in the UK.

The SM was Citroën's flagship vehicle, competing with other high performance GTs of the time from manufacturers such as Jaguar, Lotus and Porsche. It was also Citroën's way of demonstrating just how much power and performance could be accommodated in a front-wheel drive design.

The SM innovated a new type of variable assist power steering that has since spread throughout the vehicle population. It allowed great assistance to the motorist while parking, but little assistance at motorway speeds. The steering actually had the same "assist" at all speeds - the steering was hydraulically locked against steering movement of the wheels from the road ("feedback") up to the capacity of the unit. Hitting a pothole at high speed would not turn the steering wheel in the driver's hands! The hydraulic pressure to the power centering unit increased with speed, giving the impression of less and less power "assist." Enough pressure was admitted to the centering unit to return the wheels to the straight ahead position when the car was not moving. The centering pressure was regulated by a flyweight centrifugal governor driven by the pinion (secondary) shaft of the manual gearbox and by a proportioning valve connected to the pressure in the automatic gearbox, which pressure was proportional to the speed of the output shaft.

Contemporary automotive journalists were most effusive about the SM's dynamic qualities, which were unlike anything they had experienced prior. The SM provided a combination of comfort, sharp handling, and high performance not available in any other car at the time. Popular Science noted that the SM had the shortest stopping distance of any car they had tested. To this day this stopping distance remains outstanding.

Unfortunately, the SM did not find a sufficient customer base in the European GT market, but much of the SM's technology was carried forward to the successful Citroën CX, launched in 1974 - the DIRAVI steering being the most obvious example. The same basic engine in enlarged 3.0 L form (some in Italy had 2 litre) was used in Maserati's own Merak which, together with Maserati's Khamsin and Bora, used Citroën's high pressure hydraulics.

Styling

The look of the car was quite distinct. Designed in-house by Citroën's chief designer Robert Opron, the SM bore a vague family resemblance to the DS. Seen from above, the SM resembled a teardrop, with a much wider track at the front.

The SM was unusually aerodynamic for its era, with a very low drag coefficient. European critics marvelled at the resulting ability to travel for hours at 200 km/h (120 mph) in comfort. In addition, many of the details reflected Robert Opron's American background, notably the truncated 'fins' at the rear.

The SM combined many unusual features - lights that swivelled with the steering (except in the USA where such was illegal), unique self-centering and fully powered steering, self-leveling headlights (except in the USA where such was illegal), a wiper mechanism that was 'sensitive' to rain, and many other features that are now commonplace on the cars of today.

The SM's design was timeless; the car was even used in a 1999 television advertisement for British Petroleum of Spain, where 'a futuristic car was required'. It placed eleventh on Automobile Magazine's 2005 "100 Coolest Cars" listing.

In 1970, it was a car of the future and the fastest front-wheel drive car to be made. It was an example of the car as a symbol of optimism and progressive technology, similar to the SM's contemporary, the Concorde aircraft.

US exports

The main export market for the SM was the United States. In the US, the market for personal luxury cars was much larger than in Europe, with competitors like the Cadillac Eldorado, Lincoln Mark IV and Ford Thunderbird alongside a large selection of Italian, British, and German imports. Nevertheless, the unique design of the SM made quite a splash and won the Motor Trend magazine Car of the Year award in 1972: unheard of for a non-US vehicle at the time.

The SM's six headlight set up was illegal in the United States and consequently, US specification cars were fitted with four fixed round exposed lamps.

Despite initial success, US sales ceased suddenly - Citroën expected (but did not receive) an exemption for the 1974 model year 5 mph bumper regulation imposed by the NHTSA. The integral variable height suspension of the SM made compliance impossible. The final batch of 134 now illegal 1974 US model SMs were shipped to Japan.

This bumper regulation as written appeared not carefully thought through, and was repealed in 1981. The original intent was to address a fairly small economic concern, repair costs in low speed accidents. NHTSA attempted to address this issue by mandating a certain design and criminalizing any deviance from it. It called for bumpers to be an exact height off the ground at all times, yet according to the laws of physics, all cars dip at the nose on braking. Vehicles classified as trucks were always exempt.

Engines

The SM was sold with three very similar, small, lightweight engines, all derived from the contemporary Maserati V8 fitted to the Quattroporte. Because of the V8 origin, this engine sported an unusual 90 degree angle between cylinder banks - a trait shared with the PRV V6.

The engines - always mounted behind the front axle were:

2.7 L V6 with Weber 42 DCNF carburettors, "C114-1" (170 bhp) (1970-1972)
2.7 L V6 with Bosch D-Jetronic injection, "C114-03" (178 bhp) (1973-1975 - Not available in the US)
3.0 L V6 with Weber 42 DCNF carburettors, "C114-11" (180 bhp) (1973-1975 - US only in 1973, rest of the world, automatic only in 1974 & 1975)

The size of the 2.7 L engine was limited by French puissance fiscale taxation, which effectively banned large displacement vehicles. The engine was also used in the Maserati Merak from 1973 to 1982 and the Ligier JS2 sports car. The final SMs were produced in the Ligier factory in Vichy.

5 speed manual and 3 speed Borg Warner fully automatic transmissions were fitted, but with the rest of the world outside North America only getting the fully automatic in 1974 & 1975.

The C114 is a relatively sturdy unit, provided certain modifications are performed to eliminate weak points leading to catastrophic damage:

The sodium filled exhaust valves may break and drop into the cylinder. Solid valves in stainless steel and other alloys are available.
Primary distribution chains and camshaft chains may wear out prematurely. This is commonly due to due to poor chain quality. Renold Synergy is the recommended replacement chain. A curved fixed chain limiter and improved tensioner should be fitted.
Oil pump drive shaft is, in some cases, underdimensioned and may break. Maserati beefed up the shaft in later versions, and this should be retrofitted if not already present. The backspacing of the crankshaft bore accepting the oil pump shaft was too deep in early engines. Fitting a spacer will move the shaft to full engagement with the pump eliminating the need for the later pump shaft.

Demise

After the 1974 bankruptcy of Citroën, Peugeot took ownership of the company and in May 1975, divested Maserati. Peugeot decided to stop building the SM, as sales were minimal in that year.

Observers often attribute the demise of the SM to the 1973 oil crisis and economic recession. While the oil shock certainly impacted sales, it is useful to note that many far more profligate cars were introduced at the same time the SM ceased production, like the Mercedes-Benz 450SEL 6.9. Peugeot even introduced a V6 powered car of similar displacement and fuel consumption in 1975, the 604. In the USA, the SM was actually an economical vehicle relative to its competitors. However, NHTSA imposed new automotive design regulations in 1974, effectively banning the Citroën from the US market.

As illustrated under production numbers, SM sales declined starting in 1972. This appears to be attributable to maintenance issues. Most vehicles require only generalist maintenance, where any competent mechanic can properly maintain the vehicle. Certain vehicles, like Citroëns and Ferraris require specialist care due to their unique design. While a sturdy car if maintaned rigorously, the SM did require two sets of specialist care - Citroën specialists, which are widespread in Europe, and a rarer Maserati specialist, to keep the engine in tune. Once potential buyers began to realize this, sales dropped precipitously.

Components of the SM lived on - in the Maserati Merak (engine) and the Lotus Esprit (transmission). Nissan made a small three-door hatchback in the late 1970s which used many SM styling cues, including the tailgate. The successful Citroën CX carried forward most of the SM's dynamic qualities, including the trendsetting speed sensitive power steering.

Production numbers

A total of 12,920 SMs were produced during its lifetime. The production figures for individual years were:

1970: 868
1971: 4988
1972: 4036
1973: 2619
1974: 294
1975: 115

The North American market took 2,400 cars, in the years 1972 and 1973. Eliminating this impact, sales declined a dramatic 43% from 1971 to 1972 and a further 50% in 1973.

Variants

Coachbuilder Henri Chapron from Levallois-Perret produced a handful of convertibles (SM Mylord) and sedans (SM Opéra). French Presidents from Georges Pompidou to Jacques Chirac have enjoyed touring Paris in the two 4-door convertible Citroën SM présidentielle models, also converted by Chapron.

In 1971, Heuliez also produced 2 examples of a targa top convertible, the SM Espace.

Just before the SM's demise, Citroën produced several short-wheelbase racing versions with squared-off rear sections and highly tuned engines - known as the "breadvan" model.

The SM was never produced in right-hand drive although three official prototypes were constructed by Middleton Motors, a Citroën dealer in Hertfordshire, England. At least one of these prototypes still survives. Cars are currently being modified with RHD controls and dashboards for Australian sale.

Frua also proposed a concept car based on the SM, closely resembling the Merak.

SM World, a marque specialist in Los Angeles, California, has produced an extended SM pickup truck and a turbocharged SM, which set the land speed record for its class at the Bonneville Salt Flats, Utah - traveling 202 mph (327 km/h). These vehicles have both been memorialised in die-cast miniatures.

The Maserati Quattroporte II was a Maserati-badged, 4-door variant of the SM, with an angular body and lengthened floorpan. The six headlights were retained and the later 'SS' version of the engine fitted.

Appearances in art & famous owners

Like the Citroën DS, the SM has made prominent appearances in several films and TV series, and has had many celebrity owners. Emperor and religious icon Haile Selassie I of Ethiopia had an SM, while Ugandan strongman Idi Amin had seven of them. The Shah of Iran drove an SM. Actors Lorne Greene and Lee Majors, President of the USSR Leonid Brezhnev, composer John Williams, author Graham Greene, soccer star Johan Cruijff, entertainers Jay Leno, Cheech Marin, and Thomas Chong were among other prominent owners of the SM.

Burt Reynolds escapes a fleet of police cars behind the wheel of an SM in the 1974 film The Longest Yard. In the film, having driven the car to a quayside, Reynolds gets out of the car and nudges the gear lever into reverse: the car drives itself into the water. In real life, he liked the car so much that he gave an SM to his friend Dinah Shore.

Janet Jackson appears in an SM with a red leather interior in the music video for the 1998 hit song I Get Lonely from the Velvet Rope album.

Patrick McGoohan drives an SM in a 1975 episode of the American television series Columbo while Gerry Anderson's 1971 television series, The Protectors, prominently featured a platinum blue SM.

Ben Stiller is kidnapped in a green SM in the 2001 film Zoolander, and an SM is also used in an attempted kidnapping in the 1975 Charles Bronson film Breakout.

While not bearing a resemblance to any other car on the market, the SM did resemble the vehicles featured on the 1970 science fiction television program UFO.

Sven Väth and Miss Kittin drive a modified Citroën SM in their video from the single Je T'Aime Moi Non Plus. At the back of the vehicle there is a silver sign "Injection Electronique" and the front grille is in the shape of a text, namely "Miss Kittin".

References

'Citroën SM,' Osprey Autohistory, Jeff Daniels, 1981, ISBN 085045381X
'Motor Trend' magazine (USA), February 1972 issue
'Car and Driver' magazine (USA), June 1972 issue
'Popular Science' magazine (USA), December 1973 issue
'Motor Trend' magazine (USA), February 1974 issue
'Car' magazine (UK), December 1979 issue
'Collectible Automobile' magazine (USA), June 2001 issue
'Thoroughbred & Classic Cars magazine (UK), April 1995 issue
'The Longest Yard - Lockdown Edition' DVD, selection 02638, Paramount Home Entertainment, 2005