Assessment of H.T. tests (2 CV, 3 CV) and comparison of the number of parts (26.11.1968)
Handwritten assessment dated 26 November 1968: list of the eight test vehicles (2 CV and 3 CV) equipped with hydrostatic transmission with their mileages, followed by a comparison of the number of parts between a classic gearbox and hydrostatic transmission.
Understanding this document
In this document
List of test vehicles (p. 57)
The sheet summarizes eight vehicles equipped with Hydrostatic Transmission, with their start and end dates of testing and their mileage:
| No. | Vehicle | Start | End | Mileage | Remark |
|---|---|---|---|---|---|
| 1 | 2 CV (A12) | 7 Jan 1960 | 13 May 1966 | 295,660 km | "first experimental prototype" |
| 2 | 2 CV (ELV 724) | 20 Apr 1960 | 25 Apr 1966 | 31,375 km | regulation development, variable displacement pump/receiver, hydrostatic braking |
| 3 | 2 CV (ELV 640) | 18 Dec 1961 | 7 Oct 1963 | 39,877 km | — |
| 4 | 3 CV (ELV 1140) | 8 Apr 1965 | 30 Oct 1968 | 83,800 km | — |
| 5 | 3 CV (ELV 874) | 13 Jan 1966 | 13 Dec 1966 | 40,638 km | "accidented" |
| 6 | 3 CV La Ferté (ELV 1128, Labo) | Feb 1967 | ongoing | 66,536 km | — |
| 7 | 3 CV La Ferté (ELV 1294, BEA) | 13 Mar 1967 | ongoing | 106,940 km | — |
| 8 | 3 CV (BEA) | Jun 1967 | ongoing | 23,251 km | — |
The cumulative total amounts to 688,077 km p. 57, the page being dated 26.11.68 and bearing a handwritten initial.
Comparison of the number of parts (p. 58)
The document compares, in number of parts, three mechanical assemblies:
| Assembly | No. of parts | No. of parts | Coefficient |
|---|---|---|---|
| 3 CV gearbox + clutch (with control) | 187 | 357 | 1.9 |
| Hydrostatic Transmission | 210 | 398 | 1.9 |
| For reference: DS gearbox semi-automatic control | 334 | 528 | 1.58 |
A note specifies that the figure for the hydrostatic transmission "will be significantly reduced in the study in progress" p. 58.
Context
The hydrostatic transmission is an automatic transmission system with a continuously variable transmission developed at Citroën, an alternative to mechanical gearboxes and the semi-automatic control of the DS.
The vehicles cited — 2 CV and 3 CV (experimental versions of the 2 CV) — served as rolling test benches for this technology, notably on the La Ferté-Vidame endurance circuit, owned by Citroën.
The acronym BEA refers to the Bureau d'Études Automobiles (Automotive Design Office) of Citroën, where Paul Magès conducted his research.
Archivist's perspective
This summary sheet, dated 26 November 1968, seems to constitute a progress report after nearly nine years of tests on the hydrostatic transmission, totaling nearly 700,000 cumulative km p. 57.
The numerical comparison of the number of parts p. 58 illustrates a very concrete industrial concern of Magès: to justify — or question — the viability of his invention against existing solutions, with the DS control serving as a historical reference.
The mention of an expected reduction in the number of parts "in the study in progress" p. 58 shows that the project was still in active development at that date. This document usefully complements the Record of mileages of test vehicles with Hydrostatic Transmission (1960-1973) and finds a later echo in the Technical presentation by P. Magès on hydrostatic transmission.
In the same folder
Dating
26 November 1968
Document
2 pages
Source: « Scanner 18 août 2025 à 15.25.pdf », p. 57–58
Category
Archival note
p.57 date 26.11.68 in header; p.58 handwritten continuation on nomenclatures; summary p.164: "26-11-1968 List of tests of 2 and 3 CV vehicles equipped with H.T.".