Citroen SM Injection
The Citroen SM is one of the most technically ambitious and stylistically daring grand tourers ever built. Created after Citroen acquired Maserati in 1968, the SM combined Citroen's revolutionary hydropneumatic suspension technology with Maserati's quad-cam V6 engine to create a 137-mph luxury coupe unlike anything else on the road.
The name SM stood for 'Série Maserati' or 'Sport Maserati.' Robert Opron designed the sleek, aerodynamic body with a Cd of just 0.26 — exceptional for 1970 and better than most cars built today. The SM's front end featured glass-covered headlights that turned with the steering, illuminating corners before the car entered them. Six headlights were hidden behind the glass panels.
The 2.7-liter Maserati V6 was a specially developed engine featuring double overhead cams and three Weber carburetors initially, later replaced by Bosch fuel injection. Power went to the front wheels — an unusual configuration for a grand tourer, but Citroen's engineers made it work through sophisticated weight distribution and their legendary suspension.
The hydropneumatic suspension provided the same magic-carpet ride as the DS, automatically adjusting ride height and maintaining level cornering. But the SM's most revolutionary feature was DIRAVI (Direction à Rappel Asservi) — a self-centering, variable-assist power steering system that adjusted effort based on speed and linked directly to the brakes. At high speeds, the steering firmed up; at low speeds, it became light. The system automatically centered itself through hydraulic pressure — let go of the wheel and it would return to straight ahead on its own.
The SM was exotic, fast, and comfortable, combining Italian passion with French innovation. Motor Trend named it Car of the Year in 1972, the first time a European car received this honor. But the SM was expensive to produce, and the 1973 oil crisis devastated sales. Citroen's financial troubles led to a takeover by Peugeot in 1974, and SM production ended in 1975 after just 12,920 units.
Today, the SM is recognized as a masterpiece of automotive engineering and design — a car that was perhaps too advanced for its own good. Pristine examples, especially fuel-injected US-spec cars and the rare automatic transmission variants, are highly sought after by collectors who appreciate its unique combination of French and Italian genius.
The SM is a specialist car requiring deep knowledge of both Citroen hydraulics and Maserati mechanicals. The hydropneumatic system (LHM fluid) powers everything — suspension, steering, brakes, headlight leveling. Leaks are inevitable. The Maserati V6 is robust but requires specialist maintenance; Weber carburetors need expert tuning. DIRAVI steering system is complex and parts are scarce. Rust affects inner sills and subframes. The ZF manual transmission is more desirable than the automatic. French and Italian specialists are essential. Budget $10,000+ annually for maintenance on a driver-quality car.
Total production: 12,920 units (1970-1975). Carbureted cars (1970-72) produced 170 hp with triple Weber 42DCNF carburetors. Fuel-injected cars (1972-75) used Bosch D-Jetronic. US-spec cars had catalytic converters and reduced power. Automatic transmission (Borg-Warner 3-speed) was offered alongside the ZF 5-speed manual. Approximately 2,500 were sold in the United States before emissions regulations made imports impossible.