Ever forward-looking, Citroen was keen to follow NSU into production with a rotary-engined mainstream production saloon. Enter, in 1973, the Citroen GS Birotor. Although it looked superficially like Citroen's well known air-cooled saloon, it was, in respects over and above the engine, almost totally different, illustrating Citroen's commitment to the project and its completely undisciplined cost-control. Outwardly, it had flared wheel arches to accommodate wider tyres, while under the bonnet all the pressings around the bulkhead had been changed to accommodate the twin rotor Wankel engine. Good for 106 bhp, this smooth, lusty unit drove through a semi-automatic clutchless three-speed gearbox. The pundits liked the car, but potential buyers were dismayed by its fuel consumption which, in typical Wankel fashion, was on the wrong side of 18 mpg.
The Birotor was difficult to sell, and such was Citroen's humiliation with the project that it offered to buy cars back from their owners and scrap them. Only 847 were built in total, of which perhaps 200 survive. The real tragedy of Citroen's brush with the rotary engine, however, is that it never made the proposed three rotor Wankel-engined CX.