Road Test, April 1972: complete test and technical report of the Citroën SM

In this document

A complete road test

The American magazine Road Test devotes its April 1972 issue to a complete test of the Citroën SM, presented on the cover as "A Totally New Driving Experience" p. 164. The central article, unsigned but credited to the magazine, immediately highlights that this "Franco-Italian creation" was born from the union between Citroën and Maserati, and that the first production chassis (no. 00SB0003) left the Parisian assembly line in July 1970 p. 165.

The testers detail at length the vehicle's disconcerting handling: hidden ignition switch, highly geared steering (2 turns lock-to-lock) that "stiffens" with speed, brake pedal replaced by a simple rubber button with almost zero travel, and controls grouped on steering column levers p. 166. The engine, a Maserati V6 with three twin-choke Weber carburettors, is judged surprisingly flexible at low revs with a clear power surge towards 3000 rpm p. 166.

Comfort, suspension and interior

The leather seats, fully adjustable and with position "memory", are hailed as a major asset for grand touring p. 167. The article returns to the hydropneumatic suspension, inherited from the 1955 DS 19, with its four ride heights adjustable by a lever (ground clearance from 6.1 to 10 inches) and its use for changing a wheel without a classic jack — the suspension "does the work of the jack" p. 167-169.

Performance and technical specifications

The specifications table p. 170 provides in particular:

Technical report by John Ethridge

The second part, signed by John Ethridge, details the operation of the hydropneumatic system (sphere, gas, liquid, piston, height corrector cylinder, p. 171), the mechanics of the 308 lbs Maserati V6 p. 172, the fully synchronised 5-speed gearbox, the speed-sensitive steering regulator p. 172, as well as the 4-disc braking system with emergency accumulator and rear load-sensitive distributor p. 173. The 7-piston hydraulic pump provides 51.2 cubic inches/minute at idle p. 173.

Context

Historically, the Citroën SM (1970-1975) was born from the acquisition of Maserati by Citroën in 1968, allowing the combination of Italian engine expertise with the hydropneumatic suspension developed by Paul Magès since the DS 19 (1955). Road Test is part of the specialised American automotive press, whose echo counted in the international dissemination of Citroën's technical reputation, particularly in the United States where the brand sought to establish itself permanently.

Archivist's perspective

This foreign press issue testifies to the international reach obtained by Paul Magès' innovations, fifteen years after their introduction on the DS. It is notable that the article explicitly links the SM to the hydropneumatic heritage of the DS 19 p. 167, proof that the system designed by Magès remains, for the American specialised press, Citroën's major technical signature.

The handwritten annotation on the cover, probably "M. Bohers to Magès" p. 164, suggests that this copy was transmitted directly to the engineer, perhaps by a colleague or correspondent — a sign that Magès followed the reception of his inventions in the foreign press. This document usefully complements older archives on the genesis of the system, such as the Note of 11 September 1959 on hydraulic or pneumatic suspension or Magès' BBC lectures on DS suspension, by showing the commercial and media culmination of this engineering work.