The Citroen SM Turns 40
The car was produced in collaboration with the Italian sports car manufacturer Maserati (this was owned by the French Company at the time) and was revealed to the public at the Geneva Motor Show on March 11, 1970.
The car impressed through its sporty ride that didn’t sacrificed comfort and its avant-gardist styling. It was also praised for its overall build quality and high level of performance. Actually the greatest asset of the car was the fact that it combined of all these. One of the car’s most innovative features was its power steering system that offered a variable level of assistance, depending on the the vehicle’s speed. The SM rode on a hydro-pneumatic suspension which featured an automatic ride height control function. The headlamps also used an automatic leveling system.
The Citroen SM is powered by a Maserati V6 powerplant that made it one of the fastest front-wheel drive vehicles at the time, as it allowed the car to reach a top speed of 137 mph (220 km/h). The SM also entered the motorsport world, wining its first race at the Morocco Rally in 1971.
The Citroen SM has been owned by many famous international figures over the years, including Jay Leno, Rolling Stones drummer Charlie Watts, author Graham Greene and actor Lee Majors. It was also used as an official car for multiple French Presidents. These were offered bespoke 4-door convertible “presidentielle” models.
comments written so far
Much text about the SM demonstrates the writer's ignorance of the actual features and function of the SM's systems. And imagination.
Common misinformation: The engine was a Maserati V8 less 2 cylinders. Actually, Alfieri designed the engine on short order. Few parts were shared with any other Maserati engines. The 90 degree angle was to provide a low overall height and for the block to be machined on equipment also used for the V8s.
More: The headlights were operated by the central hydraulic system that operated the suspension, steering and brakes. Actually, the headlight hydraulic systems (3) were nonpowered and separate from the central system.
More: The DIRAVI steering reduced its power assist as the car went faster. Actually, the power assist was the same at all speeds. The centering force on the steering wheel increased with speed.
More: The SM front suspension is trailing link, as opposed to the DS' leading link. Actually, neither is leading or trailing. Both are lateral equal-length arms. The parts are basically the same on both the SM and D except that the swivel bearing diameter of the SM lower arm is larger than the D. The cast aluminum suspension arm swivel housings are identical to those of the D except for a hole drilled in the left hand one for the manual height control rod.
More: the SM front suspension is unequal-length, which keeps the front wheels square with the road when the car body leans. Actually, the arms are equal-length (from the swivel bearings to the ball joints), which keeps the front wheels perpendicular to the car's horizontal plane. The rear wheels are carried by swing arms that also keep the rear tires perpendicular to the car's horizontal plane.
Another misinformation bit: The car's body is of "aircraft grade" aluminum alloy. Actually, the body is almost entirely steel. The hood and under-bumper valance are aluminum. Only a few other parts of the body, all minor bits not welded to the body, are not steel. A special racing car or two were made of aluminum alloy.
"DIRAVI is insanely complicated." Actually the DIRAVI system is very little more complex than a conventional power-assisted rack-and-pinion steering. By its use of the central hydraulic system, the steering has no dedicated pump of its own.
"...if the rear of the car was loaded down, the lights would automatically adjust to point straight ahead so as not to blind oncoming motorists." This is true, but the self-leveling suspension would quickly compensate for a load in the car, front, rear or middle. The headlight leveling served only during pitching of the car body.
"The engine is only 12 1/4 inches long." I was unable to find any part of the engine castings that are 12 1/4" long. The nearest was a cylinder head. If the engine is measured from the bellhousing mating face to the rear of the engine over the water pump cover, it is considerably longer than 12 1/4".
"Credit the short stopping distance to the fact that the front brakes are inboard." The brakes being inboard has nothing to do with stopping distance. Mounting them inboard on the transaxle reduced unsprung weight and allowed the steering axis to be vertical and centered in the wheel for center-point steering. The inboard brakes did allow simple unventilated disc rotors due to superior airflow around the discs.