Citroën internal information: launch of the GS Birotor (25 July 1973)
Citroën internal press release dated 25 July 1973 announcing the launch of the GS Birotor, the first French car with a rotary engine, at the Frankfurt and Paris Motor Shows.
Understanding this document
In this document
This page is a Citroën Internal Information bulletin dated 25 July 1973, distributed internally ("placed on all factory notice boards", p. 179). It reproduces the press release sent the same day to the media, accompanied by a photo.
The announcement of the GS Birotor
The press release presents the Citroën GS Birotor as "the first French car equipped with a rotary piston engine" p. 179. Its launch schedule is specified:
| Stage | Date | Page |
|---|---|---|
| Frankfurt Motor Show | 13 September 1973 | p. 179 |
| Paris Motor Show | from 4 to 14 October 1973 | p. 179 |
| Commercialisation in France | from 1974 | p. 179 |
Announced technical specifications
The text highlights the assets inherited from the classic GS — "comfort and road holding (hydropneumatic suspension), braking and steering" — which it claims are acclaimed by "nearly half a million users" p. 179, to which the Comotor engine is added:
| Characteristic | Value | Page |
|---|---|---|
| Engine type | Comotor, 2 rotors | p. 179 |
| Displacement | 1,990 cm³ | p. 179 |
| Power | 107 DIN hp at 6,500 rpm | p. 179 |
| Performance | 34.1 s for the 1,000 m standing start | p. 179 |
The page also includes a Citroën logo, a handwritten red note "25.07 73" and a printed banner "Informations Intérieures - 22" p. 179.
Context
The Comotor engine, mentioned in the press release, was the result of a joint venture between Citroën and NSU to develop the Wankel-type rotary engine. The GS Birotor, launched in 1973, would remain a commercial failure — its production was halted in 1975, partly due to the 1973 oil crisis and the high fuel consumption of the rotary engine, despite its technologically advanced image. Today, it remains a rarity sought after by collectors.
Archivist's perspective
This document is not signed by Paul Magès and does not directly relate to his work on hydraulics; however, it illustrates the industrial context in which his work was situated: the hydropneumatic suspension, which he invented and perfected, is presented here as a full-fledged selling point, alongside a much riskier engine innovation p. 179.
It seems that this piece was kept in the Magès collection less for its technical content than as a testament to the internal distribution of Citroën press releases and the place, still central at that date, of hydropneumatics in the brand's identity — a thread that goes back to Paul Magès' BBC lectures on future improvements to the DS suspension.
In the same folder
Anonymous clinical presentation of the “L” against the DS and its rivals (March 1974)
1969 DS commercial study: customers who left and customers who came from the competition
Bernard's note to Jouny on Asnières hydraulic manufacturing (5 July 1973)
Dating
25 July 1973
Document
1 page
Source: « Scanner 8 août 2025 à 15.18.pdf », p. 179
Category
Archival note
Date 25.7.73 and title GS-BIROTOR p.179; summary entry.