Citroën SM
| Industry | Automotive |
|---|---|
| Founded | June 4, 1919 in France |
| Headquarters | France |
| Products | Automobiles |
| Website | www |
The Citroën SM is a performance-oriented coupé manufactured by the French automaker Citroën between 1970 and 1975. It achieved third place in the 1971 European Car of the Year competition, trailing the Citroën GS, and secured the Motor Trend Car of the Year title in the United States in 1972.
History
Citroën initiated 'Project S' in 1961, aiming to develop a sports version of the Citroën DS. Over nearly a decade, this project transformed into a fully engineered successor to the DS. The acquisition of Maserati by Citroën in 1968 was intended to merge Maserati’s performance-oriented V6 engines with Citroën’s advanced Hydropneumatic suspension system, culminating in an authentic Gran Tourer.
The SM was unveiled at the Geneva Motor Show in March 1970 and became available in France by September that year. Factory-produced models featured left-hand drive exclusively, with right-hand drive versions converted post-production in the United Kingdom and Australia.
Due to horsepower tax laws limiting luxury car production in post-war France, the SM was equipped with a 2.7-liter engine designed to meet these constraints. This marked France’s re-entry into the luxury and performance market since the export-centric Facel Vega, which utilized Chrysler Hemi V8 engines during the late 1950s. The SM's competitors included grand tourers from Jaguar, Ferrari, Aston Martin, Alfa Romeo, Mercedes-Benz, Porsche, and Maserati’s own Merak.
The designation 'SM' likely stems from combining Project 'S' (sports) with Maserati; it is frequently interpreted as "Système Maserati" or "Série Maserati." Another perspective suggests it stands for 'Sa Majesté' (Her Majesty), paralleling the DS’s nickname 'La déesse' (The Goddess).
Although the SM faced challenges within Europe’s niche GT segment, many of its technological advancements influenced the successful Citroën CX introduced in 1974, especially the DIRAVI steering system. Its engine, expanded to 3.0 liters (and 2.0 liters for Italy), powered Maserati’s Merak (with roughly 1,800 units produced) and later the Maserati Biturbo (approximately 40,000 units). During the Citroën-Maserati collaboration, models such as the Merak, Khamsin, and Bora incorporated Citroën’s high-pressure hydraulics and transmission technology.
Performance
Automotive reviewers of the era lauded the SM for its exceptional driving dynamics, highlighting an unprecedented combination of comfort, precise handling, and exceptional braking capabilities. Popular Science reported it had the shortest stopping distance among vehicles tested.
The SM was capable of delivering comfortable travel at sustained speeds of , making long journeys effortless. In 1972, Motor Sport (U.K.) praised its rare ability to remain engaging at any velocity. Its sizable fuel tank combined with reasonable fuel efficiency supported extended fast yet relaxed drives.
Despite having a smaller displacement engine than many rivals, acceleration was sufficient but not outstanding. Some owners opted to replace it with the more powerful Maserati Merak SS engine to boost performance markedly. Fuel consumption remained competitive relative to similar vehicles.
Technical innovations
The SM incorporated numerous groundbreaking technologies, many of which only became widespread decades later. Building upon innovations from the DS, it featured hydro-pneumatic self-leveling suspension alongside self-leveling directional headlights that swiveled with steering input—except in U.S. models where this feature was prohibited.
Citroën used the SM to demonstrate how substantial power and performance could be integrated into a front-wheel drive platform while addressing issues like torque steer. The solution involved a steering system designed to provide minimal road feedback—the driver simply points and steers without disturbance from road irregularities such as potholes at high speed.
This novel variable-assist power steering system named DIRAVI was later widely implemented in the Citroën CX and influenced automotive design broadly. DIRAVI offered strong assistance during parking maneuvers but reduced support at higher speeds by modulating hydraulic pressure to ensure consistent steering feel. It featured rapid response with only two turns from lock-to-lock, often described as go-kart-like handling.
Initially met with skepticism due to its unconventional “strong-arm” steering inputs, DIRAVI gained acclaim for its precision once drivers adapted. The fully powered self-centering system allowed near-zero caster angle on front wheels while maintaining maximum tire contact without camber alteration during cornering.
Additional technical highlights included rain-sensitive windshield wipers and an adjustable steering column accommodating both height and reach preferences. The braking system adapted from the DS employed disc brakes on all four wheels with inboard front discs cooled via large ducts. Hydraulic pressure distribution balanced front-to-rear braking forces based on rear load conditions to ensure uniform vehicle lowering under heavy braking.
Standard wheels were steel with stainless steel trim rings; however, Michelin developed lightweight fiberglass wheels as an option designed for enhanced off-road resilience. These composite wheels weighed less than half their steel counterparts and were ahead of their time technologically. Contrary to some claims, these wheels contained glass fibers rather than carbon fibers—a fact confirmed by their construction details.
Styling
Conceived internally by Citroën's lead designer Robert Opron, the SM exhibits stylistic elements shared with the Citroën CX, Citroën GS, and the Maserati Mistral. Similar to the CX, it incorporates rear fender skirts, while its streamlined teardrop silhouette narrows from a broad front stance to a slimmer rear end.
For its era, the SM was exceptionally aerodynamic, featuring a Kamm tail design and a low drag coefficient. Initially reported as 0.26, Citroën later adjusted this figure to 0.339. The air intake for ventilation is located on the bonnet in a "neutral" zone, ensuring steady airflow inside regardless of vehicle speed.
Inside, the cabin embodies a modernist design philosophy, highlighted by an oval-shaped steering wheel and instrument cluster, a manual gear lever with a chrome gate, and highly adjustable bucket seats equipped with cushioned rolls. Premium materials such as aircraft-grade aluminum for the hood and stainless steel for exterior trim contribute to both robustness and a luxurious finish.
In 1970, the SM held the distinction of being the fastest front-wheel-drive automobile, with an official top speed of , while independent assessments recorded speeds up to . It represented a symbol of technological progress and optimism comparable to the contemporary Concorde airliner.
The SM secured the eleventh position on Automobile Magazine’s 2005 list of the "100 Coolest Cars."
US exports
The United States represented the SM's main export destination, where consumer interest in personal luxury cars surpassed that in Europe. Its rivals included models like the Cadillac Eldorado, Lincoln Mark IV, and Ford Thunderbird, alongside various Italian, British, and German imports. The SM's distinctive styling earned it Motor Trend magazine’s 1972 Car of the Year award—an uncommon accolade for an imported vehicle.
Nevertheless, its pioneering six-bulb composite halogen headlamp system with swiveling high beams was prohibited in the U.S., which required two or four round sealed-beam lamps mounted rigidly without lenses. As a result, SMs destined for the American market were equipped with four exposed round sealed-beam headlights.
Despite initial strong sales, U.S. distribution ceased abruptly when Citroën was unable to obtain an exemption from the 1974 bumper regulations enforced by the NHTSA. The SM’s integrated variable height suspension prevented compliance with these standards. Of the 134 units manufactured for the 1974 U.S. market, none were sold domestically; instead, they were redirected to Japan.
Engines
The SM utilized a compact and lightweight V6 engine developed by Giulio Alfieri, designed to be produced using existing tooling from the Maserati V8 engine. Its unique 90° bank angle—later adopted in the PRV V6—permitted use of a single cylinder head pattern along with an intermediate shaft driving auxiliary components.
Made from aluminum, this powerplant weighed only and was installed behind the front axle.[1]
| Model | Serial number | Engine | Displacement cc |
Fuel supply | Power (DIN) |
Transmission/ N° gears |
Weight | Top Speed | Years of production |
Number produced |
| SM 2.7 | type SB | C114-1 | 2,670 | 3 Weber carburetors 42DCNF |
170 PS (125 kW; 168 hp) | M/5 | 1,450 kg (3,197 lb) | 220 km/h (137 mph) | 1970–72 | 7,133 |
| SM 2.7 Automatique | type SB | C114-1 | 3 Weber carburetors 42DCNF |
A/3 | 1,480 kg (3,263 lb) | 205 km/h (127 mph) | 1972 | 675 | ||
| SM 2.7 Injection | type SC | C114-3 | Electronic Injection Bosch D-Jetronic |
178 PS (131 kW; 176 hp) | M/5 | 1,490 kg (3,285 lb) | 228 km/h (142 mph) | 1972–75 | 3,500 | |
| SM 3.0 | type SD | C114-11 | 2,965 | 3 Weber carburetors 42DCNF |
180 PS (132 kW; 178 hp) | M/5 | 1,450 kg (3,197 lb) | 225 km/h (140 mph) | 1973 | 600 |
| SM 3.0 Automatique | type SD | C114-11 | 3 Weber carburetors 42DCNF |
A/3 | 1,480 kg (3,263 lb) | 205 km/h (127 mph) | 1973–75 | 1,012 |
The 2.7 L engine size was limited due to French puissance fiscale tax regulations that discouraged larger engines domestically.[2]
One prototype SM was equipped with a Maserati V8 as part of development work for the 1974 Maserati Quattroporte II, generating , which significantly boosted performance.[3][4]
Another example was fitted with a twin-turbocharged V6 created by Jerry Hathaway (SM World) aimed at setting land speed records at Bonneville Salt Flats, achieving .[5]
The majority of SM vehicles came with smooth-operating 5-speed manual gearboxes.[6] A Borg Warner 3-speed automatic transmission was offered in North America (1972–73) and Europe (1974–75).
This V6 also powered the Maserati Merak from 1972 through 1982; later Merak SS models produced more output thanks to larger valves. The engine was similarly used in the Ligier JS2 sports car. Final assembly of SMs took place at the Ligier factory in Vichy.
After Maserati changed ownership, turbocharging technology was applied to this engine for use in the 1981 Maserati Biturbo, resulting in roughly 40,000 units sold.
Motorsport
The SM achieved victory in its inaugural competitive outing at the challenging 1971 Rallye du Maroc. Citroën continued to refine the SM for rally competition, including the creation of a short-wheelbase "breadvan" racing model.
Los Angeles-based specialist SM World engineered a turbocharged version of the SM, which established the production vehicle land speed record in its category at Utah’s Bonneville Salt Flats in 1987, reaching .
Demise
After Citroën declared bankruptcy in 1974, Peugeot took over the company and divested from Maserati by May 1975. Peugeot promptly ended SM production, which had dwindled to just 294 units in 1974 and further decreased to 115 in its final year.
Although often attributed to the 1973 oil crisis and economic downturn, the SM’s decline was also influenced by maintenance difficulties. While it remained comparatively economical against rivals in the U.S. market, new safety standards introduced by the National Highway Traffic Safety Administration (NHTSA) in 1974 effectively prohibited the SM from entering its main export market.
Sales started to drop in 1972 primarily due to upkeep problems. The Weber carburetors demanded frequent adjustments, and many engines experienced failure near 60,000 km because of issues with timing chain tension—complications not widely recognized by owners or mechanics at that time. The SM’s distinctive 90° V6 engine design was unfamiliar to most service technicians, adding complexity to maintenance. Additionally, ignition breaker cassette reliability posed challenges until remedied through retrofitting.
Unlike conventional vehicles, the SM required expertise from two specialist groups: Citroën technicians common across Europe and rarer Maserati specialists for engine tuning. This dual dependency significantly contributed to declining sales.
The shutdown of Citroën’s Quai André-Citroën plant in Paris in 1974 necessitated production relocation; final DS series cars were assembled at Aulnay-sous-Bois, while Ligier completed the last 135 SM units.
Components of the SM found continued use elsewhere: its engine and transmission were mirrored in the Maserati Merak, while its transmission influenced the Lotus Esprit. The successful Citroën CX inherited numerous dynamic features from the SM, including advanced speed-sensitive power steering.
Production numbers
In total, 12,920 SM models were manufactured. After the initial full production year, sales dropped sharply. North American markets accounted for approximately 2,400 units sold during 1972 and 1973.
| Year | Europe/Asia/Middle East/Africa | Sales Change | U.S. and Canada | >>TOTAL>> |
|---|---|---|---|---|
| 1970 | 868 | – | 0 | 868 |
| 1971 | 4,988 | 475% | 0 | 4,988 |
| 1972 | 2,786 | (44%) | 1,250 | 4,036 |
| 1973 | 1,469 | (47%) | 1,150 | 2,619 |
| 1974 | 294 | (80%) | 0 | 294 |
| 1975 | 115 | (61%) | 0 | 115 |
Variants
The factory offered only one body configuration: a left-hand drive two-door fastback fixed-head coupé. Nevertheless, this design inspired several exclusive derivatives.
Coachbuilder Henri Chapron crafted collectible variations such as two four-door convertible Citroën SM présidentielle editions employed by French Presidents from Georges Pompidou through Jacques Chirac. These cars featured an extended chassis, manual gearbox with low gearing tailored for parade speeds, a rear-facing folding seat, and an electrically operated convertible roof. They remained in official use for 37 years with mileage around 25,000 km.
Chapron also produced five convertibles known as SM Mylord and seven sedans called SM Opéra. These rare examples command high values; one SM Mylord sold for €548,320 in 2014. The factory never authorized convertible versions due to structural integrity concerns—the roof and rear quarter panels were permanently welded on.
In 1971, Heuliez manufactured two pillarless targa top convertibles named the SM Espace featuring retractable rear quarter windows.
Prior to production cessation, Citroën developed short-wheelbase "breadvan" racing variants characterized by squared-off rear sections and enhanced engines.
Right-hand drive (RHD) prototypes were created by Middleton Motors in the UK; at least one remains extant. In Australia, Chappel Engineering converted a dozen vehicles to RHD for importer Dutton's. RHD conversions persist today to meet market demands.
In the United States, approximately one hundred cars were fitted with an electric sliding steel sunroof by American Specialty Cars (ASC).
Designer Pietro Frua proposed a front-wheel-drive concept resembling the Maserati Merak.
In early 1974, Maserati engineered a unique high-performance V8 engine delivering 260 HP with a displacement of 4.0 L based on the C114-11 variant. This engine was installed into a standard SM and subjected to over 12,000 km of testing; while the vehicle was subsequently destroyed by Alejandro de Tomaso, the engine was preserved. The SM Club of France later constructed an exact replica displayed at Rétromobile in 2010.
The intended recipient never obtained this V8-powered car. Instead, Maserati launched the Quattroporte II—a four-door derivative of the SM featuring an angular body style and lengthened floorpan while retaining six headlights and equipped with the 'SS' engine version. Introduced during Citroën's bankruptcy period in 1974, only twelve units were produced between 1976 and 1978.
Distinguished Owners
The SM, much like the Citroën DS, was favored by numerous high-profile individuals. Among its distinguished users were Leonid Brezhnev, General Secretary of the Communist Party of the USSR, Bill Wyman, bassist for the Rolling Stones, Adam Clayton from U2, and Emperor Haile Selassie I of Ethiopia. Notably, Ugandan ruler Idi Amin possessed a collection of seven SMs, while The Shah of Iran was also known to operate one.
Additional well-known owners encompassed actors such as Lorne Greene and Lee Majors, composer John Williams, novelist Graham Greene, politician Sir Gaetan Duval, football legend Johan Cruijff, drummer for the Rolling Stones Charlie Watts, comedy duo members Cheech & Chong (Cheech Marin and Thomas Chong), motorcycle champion Mike Hailwood, as well as composers John Barry and musician Carlos Santana. The Yugoslav and Croatian singer Mišo Kovač gained recognition for owning a distinctive golden SM.
By 2019, Coldplay's bassist Guy Berryman was reported to drive an SM. Additionally, television presenter and comedian Jay Leno regularly showcases his SM in episodes of his series Jay Leno's Garage.
Bibliography
- 'Citroën SM,' Osprey Autohistory, Jeff Daniels, 1981,
- '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, Paramount Home Entertainment, 2005
External links
- Ate Up With Motor: She Likes Whips and Chains: The Pleasures and Pains of the Citroën SM – a retrospective look at the SM's design features and market influence
- Curbside Classic: 1972 Citroen SM – Gran Touring, Franco-Italian Style – analysis of the SM’s design philosophy and commercial approach
- Citroen SM Wiki
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