The Citroën SM Story

For those that would like to know how the SM came about and it’s engineering virtues, this video is a worthwhile watch:

However, note that there are few factual errors:

First, about the engine; The host states that Citroën was developing a Wankel bi-rotor engine for the SM but they abandoned it. Actually, the single-rotor Wankel engine that they tested (on customers) with the 267 M35 Ami coupes, built from 1969 to 1971, gave way to Citroën fitting a dual-rotor Wankel engine into the GS Birotor launched in 1973. It was quickly pulled from the market after only 847 GS Birotors were sold.

The SM engine is not a chopped V8. The Maserati Bora was equipped with a V8 and many have claimed that engine had 2 cylinders lobbed off to fit in an SM. Not so. The SM V6 engine was designed from scratch by Maserati’s Giulio Alfieri but capable of being assembled on existing V8 tooling. Because of this, the engine sported an unusual 90° angle between cylinder banks. The SM’s V6 engine also was used in the Maserati Merak.

The video leaves the impression that although the headlights on the SM are self levelling, that this was a new feature to the model when, in fact, the headlights of the DS also had had self levelling capability years before the introduction of the SM.

It also leaves the impression that all SMs came standard with lightweight carbon reinforced resin wheels. They were an option for those that didn’t want the rolling weight of steel rims.

The host claims that the SM offered an innovative mushroom brake pedal, but that could be found in the Citroën DS from 1955. And he goes on to say that the limited travel of brake pedal didn’t inspire confidence, when in fact Citroën encouraged sales people demonstrating the car to customers to take them on a test drive. One trick to demonstrate the braking superiority was to get up to speed on the road and drive off to the side so that two wheels were now on gravel or grass. Then, with hands off the steering wheel, nail the brake pedal. The SM would come to straight and controlled stop and often at that point, the customer would agree to buy the car. Another point that was touted is that the location of the mushroom pedal, just lightly lower than than the gas pedal, allowed for a faster reaction time as the driver only had to slide across to it rather than lift a foot to reach a conventional brake pedal.

One final clarification; the video makes it look like Citroën only made small cars after the merger with Peugeot. The CX, though not offered as a coupe, carried on the luxury brand model in the wake of the DS.

Other than these missteps, the video is a great primer on the virtues of the SM.