Citroën M35 Wankel Prototype - one of 500 (267)

The Citroën history is full of crazy stories and the M35 wrote a special one. It works like this: Those responsible shifted the testing of the new drive concept with Wankel engine into the hands of the customers. They had to qualify to participate and of course they had to pay. They probably even liked doing it. Because they were traveling in a very exclusive vehicle that was only available for testing the rotary piston engine. Today that sounds absurd and is hard to imagine. But by the late 1960s, Wankel fever was rampant. Anyone who wanted to be innovative relied on Felix Wankel's invention.

Citroën M35 Prototype No. 401
Citroën M35 Prototype No. 401

Citroën in the Wankel engine fever

Citroën, at that time still independent and not under the Peugeot umbrella, even went so far as to set up the company together with NSU comotor to found. The brands wanted to produce Wankel engines on a large scale in a joint factory, but this never happened. Technical problems, lack of financial resources and the energy crisis (!) in the early 1970s forced the project to fail.

But before that, Citroën launched the M1969 in 35 as an official test vehicle. Based on the AMI 8, the French built a new vehicle. Which in itself was a crazy and expensive idea. There should be 500 M35 prototypes. For this purpose, the AMI 8 floor assembly was newly clad, which body specialist Heuliez took over.

Normal - all M35s were identified as prototypes on the fender
Normal - all M35s were identified as prototypes on the fender

A 2CV derivative with a rotary piston engine

Since customers were previously mostly mobile with a DS in the upper class, Citroën had to offer approximately comparable technology and design. A depleted version of the hydropneumatics, leather armchairs, a redesigned steering wheel and visual improvements should ensure an appealing atmosphere in the M35.

Nevertheless, the M35 remained a 2CV derivative, albeit with a rotary piston engine under the hood. Also the only 2CV descendant that ever got hydropneumatics.

Frequent Citroën customers in France were allowed to apply for one of the vehicles. At least 30.000 kilometers annual mileage were the basic requirement. If the application found favor, then 14.000 francs had to be paid, which roughly corresponded to the price of a new D Spécial at the time.

There was then a newly clad small car. Or the vision of the future. Depending on your point of view.

The prototype is also indicated on the rear window
The prototype is also indicated on the rear window

After all, the brand with the double angle sold something like an all-round carefree package with the Citroën M35. If there was a breakdown, the manufacturer provided a replacement car free of charge. He also paid for the repair and service costs. In principle, only the petrol, from which the Wankel engine drank a lot, tires and brakes had to be paid for.

The M35 was built at the factory in Rennes-La Janais, where today the C5 Aircross running off the belts, mounted. Most of it had to be done by hand, the costs were high and the brand was losing money with every car. In addition, the first vehicles already provided enough data that Citroën pragmatically went from serial number 175 to number 376, and by the spring of 1971 only 267 M35 prototypes had been built.

Leather armchairs should create an upper-class atmosphere
Leather armchairs should create an upper-class atmosphere

Citroën collects the M35 Wankel prototypes

Then the test series ended and Citroën bought back some of the vehicles. The majority of the test customers should have responded to this. Anyone who wanted to keep their M35 Wankel could do so. However, he had to release the manufacturer in writing from warranty claims and the supply of spare parts.

The history of the M35 did not end there. Because what was actually intended for the scrap press was put away. A number of Citroën Wankel prototypes are said to have been parked on the in-house test track well into the 1980s. Gradually they were sold, flowed back into the car trade and were thus preserved for posterity.

A new steering wheel, other fittings and other details should hide the 2CV derivative
A new steering wheel, other fittings and other details should hide the 2CV derivative

The M35 is still moving on

Today there is an exemplary active scene around the Citroën M35 Wankel prototypes. There is an M35 Sign up, when a prototype is for sale it is reported and parts are remanufactured by dealers. It was once the case that only French drivers could enjoy the very special 2CV derivatives, but the M35 has now spread throughout Europe.

Prototype 401 is currently for sale. In a very original condition, it is picked up by SAS ACL in Chagny Classic Traders offered. At that time, all vehicles had the number on the fender and the reference to a prototype. Citroën proudly looked into the Wankel future, everyone should know.

Prototype 401 is yet another one of those vehicles that it is hoped will be carefully restored so that automotive history is not erased.

The rotary piston engine in the M35 is easy to drive today, the diseases of the past have been cured. The type of drive itself is not dead either. Operated with hydrogen, the Wankel Supertec calculates opportunities for the future.

Featuring visuals from SAS ACL

5 thoughts on "Citroën M35 Wankel Prototype - one of 500 (267)"

  • blank

    Charming post!
    ... but not all Citroën were necessarily beautiful! 😉
    (although I think the seats are very cool again!)

    ... but somehow I find (especially lately somehow more) that "hatchback" is actually the ideal shape for a car! ... and also (at least from Saab always) pretty !!!! 🙂
    (Okay, old “Passat” and the like are of course an exception again) 😉

  • blank

    An incredibly charming "side note" of automotive history...

    • blank

      I think I actually once saw an M35 live as a small child in the presence of my father (Dr Ing, mechanical engineering, energy and process engineering). I seem to remember that he was a little over the moon...

      And I know for a fact that I had a plastic model of the principle of change, which I didn't even begin to understand as a small child. You could spin a "piston" by hand in a less-than-perfect "circle" that appeared simultaneously and oddly off-center, yet with three corners always ran cleanly along an edge. The model was multicolored and there were two gaps in the outer edge (inlet and outlet) ...

      To this day I don't know whether you could theoretically build a Wankel that runs (energy) more efficiently and as reliably as a piston engine. But I understood the fascination with Wankel. And it goes damn well with Citroën.

      The suggested teardrop shape alone makes the M35 likeable to me. You dared and tried something. Those were real great moments in the more than 100-year history of automobile construction...

      Chapeau to the company management and the engineers and designers involved.

  • blank

    another educational journey. I vaguely remember the Birotor (?) GS. I think it was in series. The M35 is new to me. It's kind of a bit whimsical, isn't it?

  • blank

    Charming. A great topic, there is now even at least one M35 in Germany. However, it has been completely restored.

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