A racing car tamed by tax law — and made brilliant by it.
The Citroën SM is a high-performance coupé produced by Citroën from 1970 to 1975, featuring a 2.7 L V6 engine and front-engine, front-wheel-drive layout. It was developed as a Gran Tourer using Maserati's engine technology and Citroën's suspension, debuted at the 1970 Geneva Motor Show, and sold initially in France in September 1970. All factory-produced units were left-hand-drive, and its design was constrained by French puissance fiscale taxation.
It started life as a Le Mans racer before becoming France’s first post-war grand tourer.
2:24
Geneva to Garage
Maserati’s engine and Citroën’s suspension merged in Geneva — then hit French showrooms months later.
3:44
Taxed Into Shape
French tax law forced a 2.7 L engine and locked the car into left-hand drive.
5:06
Opron’s Workshop Finale
Robert Opron’s first clean-sheet design — and the last model built at Citroën’s Rue du Théâtre workshop.
6:51
American Approval
It won Motor Trend Car of the Year in 1972 — proof its contradictions worked abroad.
Worth your time?
Yes. Drive the whole thing.
4.5/ 5
What works
It integrates Maserati’s high-revving V6 with Citroën’s self-levelling suspension to deliver long-distance composure and high-speed stability.
Its low drag coefficient and compact frontal area suit sustained motorway travel.
What does not
It does not offer rear-wheel drive dynamics.
It does not accommodate right-hand-drive markets natively.
It does not exceed the 2.7 L displacement limit imposed by French puissance fiscale tax.
Drive it if
It is for drivers who value technical coherence over convention — those who accept trade-offs in service of a singular vision.
It is not for buyers needing practicality, right-hand-drive compatibility, or mainstream service infrastructure.
Skip it if
It is not for buyers needing practicality, right-hand-drive compatibility, or mainstream service infrastructure.
The written brief1 min read
What the car is and where it came from
A high-performance coupé developed by Citroën from 1970 to 1975. It began as Projet S — a Le Mans–suitable racing car — then evolved under Robert Opron and Pierre Bercot into a premium Grand Routier. It debuted at the 1970 Geneva Motor Show and went on sale in France in September 1970.
How it works, in terms someone would actually use
Front-wheel drive delivers direct steering response and traction in wet conditions. The hydropneumatic suspension isolates the cabin from road shocks but adds complexity to maintenance. The 2.7 L V6 sits ahead of the front axle, feeding power to the front wheels — a layout that demands precise weight distribution and sharp steering calibration.
What it gets right
It integrates Maserati’s high-revving V6 with Citroën’s self-levelling suspension to deliver long-distance composure and high-speed stability. Its low drag coefficient and compact frontal area suit sustained motorway travel.
What it does not
It does not offer rear-wheel drive dynamics. It does not accommodate right-hand-drive markets natively. It does not exceed the 2.7 L displacement limit imposed by French puissance fiscale tax.
What it changed
It proved a front-wheel-drive grand tourer could be both technically audacious and commercially viable in regulated markets — though only for five years, and only in left-hand-drive form.
Who it is for, and who it is not
It is for drivers who value technical coherence over convention — those who accept trade-offs in service of a singular vision. It is not for buyers needing practicality, right-hand-drive compatibility, or mainstream service infrastructure.
Is it worth your time
Yes — if you want to understand how French engineering ambition collided with fiscal reality, and how a racing prototype became a legally constrained grand tourer.
The first car to prove front-wheel drive, unitary construction, and four-wheel independent suspension could coexist in a mass-produced saloon — not as a prototype, but as a factory reality.