Paul Magès' note on the feasibility of an L vehicle at 16,000 F (11 April 1971)

In this document

This 5-page handwritten note, dated and signed "P. Magès 11.4.71" p. 151, seeks to demonstrate that "it is possible to make a vehicle at 16,000 F with a 2.4 [litre] D engine" p. 148, using two "by difference" reasoning methods.

First demonstration: the L vehicle derived from the G

Magès compares the dimensions of the G vehicle with the Peugeot 504: width, length, surface area and track are tabulated p. 148.

He argues that the increase in body surface area of the G to obtain an L vehicle would be approximately 0.96 m² p. 148, and refuses to estimate the additional cost using a simple rule of three: the panels, doors, grille, and seats do not change in weight with the width p. 148.

He calculates: G comfort bodywork at 5225 F, "transverse 4-cyl. D with ground connection" mechanics at 8810 F, plus supplements (200 F), for a total of 14,595 F, leaving a margin of 1390 F for finishing, against a target of 16,000 F p. 149. The target total weight is 1140 kg, for a price per kilo of 14 F, compared to 13F90 for the G comfort and 14F90 for the G Club p. 149-150. A comparison is also made with the 504 (13 F/kg) and a hypothetical hydropneumatic 504 (13F50/kg) p. 150.

Second demonstration: the L vehicle derived from the 1969 specifications

Starting again from the "specifications of 23.9.69" (flat 4-cyl. 1640 cm³, estimated at 15,480 F including 8330 F for mechanics and 7150 F for bodywork, weight 1100 kg), Magès substitutes the transverse 4-cyl. D mechanics (8810 F) and arrives at 15,973 F p. 150.

Conclusion and remarks

Both "by difference" studies lead to the same result, with the one starting from the G being judged "more exact" p. 151. Magès insists on the need for an optional converter gearbox, deemed "absolutely necessary" for the vehicle's image p. 151, and discusses the track of the future vehicle (1420 to 1470 mm) without significant additional bodywork costs p. 151.

Considerations on the engine (p. 152)

Magès considers, if the fiscal power is decisive, reducing the displacement of the D engine rather than creating a new 1800 cm³ 4-cylinder flat water-cooled engine. He compares this project to the Wankel engine, deemed more expensive and less durable. He mentions that an engine had been "made and tested 'in spare time'" despite the cancellation of the 1969 L, and warns of the risk that this delay might weigh on the "March 1974 deadline" p. 152.

Context

The "G" vehicle designated here corresponds, in the internal Citroën vocabulary of the time, to a project that would historically become the CX (launched in 1974); the "L" vehicle mentioned refers to reflections on an intermediate model, in line with what would lead to the GS/GSA or parallel studies. The Peugeot 504, cited in comparison, was then a benchmark in the family segment. The Wankel engine was the subject of an industrial partnership between Citroën and NSU (Comotor) at the turn of the 1970s, before being abandoned due to its costs and reliability — which the note already anticipates.

Archivist's perspective

This document illustrates Magès' working method: beyond his role as the inventor of the hydropneumatic suspension, he appears here as an engineer-economist, capable of reasoning in costs per kilogram and industrial margins for manoeuvre p. 149-150.

It seems that this note is a continuation of the reflections on the AP suspension, where the question of the balance between cost and technical sophistication of the ground connection was already being raised.

The mention of the "March 1974 deadline" p. 152 is probably an internal reference to a development schedule, no doubt linked to the project that would become the CX — a milestone that the archivist cannot, however, state with certainty, for lack of explicit precision in the text.