Citroën SM (1970)
The SM was the result of Citroën buying Maserati in 1968. Using the Italian firm’s 2.7-litre V6 engine endowed the Citroën with decent performance, but it also had to power the car’s hydro-pneumatic suspension and brakes borrowed from the DS. Along with headlights that turned with the steering and advanced dials, the SM was as advanced as it was fragile.
The fragility meant regular maintenance was vital to keep the Maserati V6 engine ticking as it should and Citroën’s suspension working. Even so, the SM earned a reputation for being fearsomely difficult to keep running correctly and it’s only now the car is really appreciated as the clever machine it is.
Citroën Birotor (1973)
Citroën more than dabbled with the notion of rotary power for its cars, but ultimately it decided against this design after experimenting with the Birotor. It used a Comotor 624 twin rotor engine as seen in the NSU Ro80 and it turned the GS base vehicle into a fast, refined cruiser. Citroën tested the car with 847 built and supplied to the public.
However, when Peugeot bought Citroën, the Birotor project was scrapped and most of the cars suffered the same fate when Peugeot bought them back. It felt the engine’s complex and unreliable nature would damage the Citroën brand, so the few surviving Birotors offer an enticing glimpse of how Citroën might have developed if it had remained independent.
