Citroën M35
When Felix Wankel first presented his rotary piston engine to experts and the press in Munich on January 19, 1960, he could hardly have imagined what was to follow. A flood of carmakers were practically knocking on his workshop door to be able to participate in this new drive concept. NSU had already made a start years earlier. The first series-produced passenger car with an “NSU/Wankel system engine” as built there. However, this was quickly followed by further developments from well-known and even lesser-known brands all over the world. In addition to Mazda and Mercedes-Benz, these included Alfa Romeo, Rolls-Royce, VEB IFA (GDR), Porsche, Nissan, General Motors and Suzuki. However, only Mazda and NSU actually brought the rotary engine into series production – or not? At this point, the question first arises as to the number of units from which one speaks of series production. Because two models, each of which produced in three-digit numbers, were made in France.
Comotor as a Franco-German cooperation
In fact, Citroën also worked on the rotary engine based on the Wankel principle, although they never signed an official license agreement with the rights holder at NSU. Instead, this cooperation existed with the Comotor company from Luxembourg, in which Citroën held shares. In this way, it was possible to hide the intended business relationship from the competition, at least for a time. Fast search queries via internet weren’t yet possible at that time. Citroën and NSU planned a joint vehicle project with the engine invented by Felix Wankel. There were to be two model versions, one to be marketed by each manufacturer. In 1967, the two companies jointly founded Comotor and began building a new plant in Altforweiler near Saarlouis. Initially, 25 rotary engines were to be produced there every day, and after a planned expansion, up to 500. To put it in a nutshell: This never happened. At times, surfboards were produced in that plant.
M35 with Ami 8 design
Between 1967 and 1969, Citroën engineers worked at NSU to learn about rotary engine technology. This led to the premiere of the M35 as the first production-ready Citroën with such an engine. Strictly speaking, the installed single-disc engine with around 0.5 liters of chamber volume and 36 kW/49 hp could be described as a halved Ro 80 engine from NSU. It was also built there, as the new plant in Altforweiler wasn’t yet ready. Citroën used its own portfolio for body and chassis parts. Thus, the Ami 8 supplied large parts of the front end, lights and the rear fenders. The latter came from the commercial vehicle version and were shortened. Heuliez was responsible for the other sheet metal work and designed a coupé with a long hatchback. For final assembly, the bodyshells and engines went to Citroën plant in Rennes.
267 vehicles instead of the 500 planned
Unlike the Ami 8, the M35 used a hydropneumatic suspension, which was later used in a similar design in the Citroën GS. The body was exclusively available in a grey-silver color; inside all M35s were upholstered in black leather. Originally, Comotor wanted to use this model to publicize the rotary engine technology in France and to identify possible problems before the start of series production in the new factory. Therefore, 500 units were to be sold to long-time Citroën customers whose driving profile showed a lot of mileage per year. Due to the price on par with the ID19, interest was limited, so only 267 were built until early 1971. Citroën subsequently tried to buy back as many M35s as possible in order to scrap them and not have to build up large stocks of spare parts. As a result, there are only a few examples left in the world. The experience gained from the M35 was incorporated into the GS Birotor, of which 847 were built.
Images: Citroën
