BEA Allera-Magès note: weight distribution of vehicle G and price estimate for the 1971 L

In this document

Weight and price distribution of vehicle G (p. 153)

The note, signed "MM. ALLERA-MAGES" and addressed to Messrs. Barthélémy, Estaque/Larousse, Grosseau, Opron and Renaud, first details the dry weight of vehicle G: 853 kg (856.5 kg with 5 litres). The distribution is between the powertrain (21%, 179.6 kg), ground connection (22.8%, 195.1 kg), structure (33.1%, 283.3 kg) and fittings (23.1%, 198.5 kg), for a mechanical total of 371.2 kg and a bodywork total of 481.8 kg p. 153.

A breakdown of bodywork items is provided:

(p. 153)

The prices are then compared: the G Confort is at 11,809 F (including 6,584 F mechanical and 5,225 F bodywork), the G Club at 12,700 F, i.e., a difference of 891 F in bodywork price, brought to 6,116 F for the Club bodywork. The price per kilo is calculated at 17.75 F for the mechanicals and 12.61 F for the Club bodywork — these two values are circled in red pencil p. 153.

Price estimate for the 1971 vehicle L (p. 154-155)

The document then extrapolates the price of the 1971 vehicle L, derived from the G Club. The 4-cylinder transverse mechanicals are estimated at 8,810 F, to which 150 F is added related to the adaptation of the frame (front cradle + rear frame versus a single frame), i.e., a mechanical total of 8,960 F.

The surface areas are compared: G = 1.610 x 4.120 = 6.63 m², L = 1.710 x 4.400 = 7.52 m², i.e., an increase of 0.89 m² and an L/G ratio of 1.14 p. 154.

Assuming the weight is proportional to the surface area, the increase in bodywork weight is estimated at 65 kg, then at an additional price of 820 F, bringing the bodywork to 6,936 F and the total vehicle to 15,896 F. The text specifies that this reasoning is done "by excess"; by counting only the material price (50 kg at 5 F), the total price falls to 15,326 F p. 154.

The note concludes that "this study is done to see if there is any chance of being able to make an L at 16,000 F", that "the margin of guarantee is extremely low" but that the comparison to the G Club "should not be ridiculous" p. 155.

Context

In Citroën's history, "vehicle G" refers to the project that would lead to the GS, launched in 1970; "vehicle L" refers to the subsequent development that would give birth to the CX (launched in 1974). Robert Opron, cited as a recipient, was then the chief stylist at Citroën. These connections are part of general historical knowledge and are not explicitly stated as such in the document.

Archivist's perspective

This note illustrates a lesser-known aspect of the work of Paul Magès and the Design Office: beyond the engineering of the hydropneumatic suspension, he participated in fine economic trade-offs, mixing technical calculation and industrial cost estimation.

The document testifies to a method of reasoning by extrapolation (weight/surface/price), assumed to be approximate "by excess" p. 154, revealing the rigour but also the methodological honesty of the design office.

It seems to be in line with the technical reflections conducted since the 1960 BBC conferences, where Magès was already discussing the future developments of the Citroën range.