Citroën SM

Overview

Citroën bought Maserati in 1968 for one reason: it had a car in mind and no engine to put in it. Project S was meant to be a fast DS, and the four cylinder sitting on Citroën's shelf was never going to carry it. Giulio Alfieri's answer was a 90 degree quad-cam V6 of 2,670cc, sized deliberately to stay inside the French fiscal horsepower band, and it went into a machine unlike anything else on sale when the covers came off at Geneva in March 1970. The SM took the DS's hydropneumatic suspension and pushed every other system to the same extreme. Discs at all four corners, the fronts mounted inboard. A brake pedal that was a pressure-sensitive mushroom rather than a lever. Six headlamps behind a single curved glass panel, self-levelling, with the inner pair swivelling with the front wheels. DIRAVI steering geared at two turns lock to lock that dragged itself back to centre whether the engine was running or not. Nobody had put this many ideas into one road car before, and after the 1973 oil crisis and Peugeot's takeover nobody has since. Five years and 12,920 cars later it was over.

Distinctions

The defining attributes and collector status that make this car garage-worthy.

Octane Files Select

Renowned for its history, engineering, or cultural weight.

Collectibility scorecard

Rated 1 to 10 on the traits that matter for owning, driving, and holding on to a car like this.

Desirability

7/10

Rarity

7/10

Driving thrill

6/10

Investment trajectory

5/10

Usability

5/10

Ease of restoration

3/10

Cultural impact

6/10

Electronic dependence

Fully analogHeavily electronic

Everything that makes the SM feel advanced is hydraulic rather than electronic. Suspension, DIRAVI steering, braking and headlamp levelling all run off one engine-driven high-pressure LHM circuit with no processor anywhere in it, and ignition is a conventional contact-breaker distributor. Cars built from 1970 to 1972 breathe through three Weber 42DCNF carburettors and are fully analogue. What lifts the generation off the bottom of the scale is the Bosch D-Jetronic fitted to 2.7 litre cars from late 1972, an early analogue engine-management system reading manifold pressure and throttle position. It is the only computer in the car, and all it controls is the injectors.

Market data

Demand tier, price trend, and typical values by condition. Our own assessment, not a quoted valuation.

Demand tier

EntrySolidHighBlue-chip

A dependable market. Well-kept cars hold their value and find ready buyers.

Value trajectory

AppreciatingStableCooling

Values are holding steady. What you pay today is what it's worth tomorrow.

Price by condition

Driver

$30k

Excellent

$60k

Concours

$95k

The SM has spent thirty years being described as underpriced, and the spread of recent results shows why nobody has settled the argument. CLASSIC.COM's highest recorded SM sale is a 1973 car at $95,200 through Broad Arrow at Amelia Island in March 2025, while a 1972 example brought $23,650 at Mecum's Indy Fall Special in October 2025. Sales logged in late July 2026 landed at $35,250 and £72,000. That range is not really about year or engine. It is about whether the hydraulics and the timing chains have been kept up, because a neglected car carries a five-figure bill that a good one does not, and buyers price that in. Values have crept up rather than climbed, and the ceiling has been reset only recently. The tier reflects genuine scarcity and a devoted following held back by a small pool of specialists and a reputation for complexity that keeps casual money away.

Values as of August 2026.

Buyer's guide

What anyone seriously considering this car should know first.

Why it's worth it

The fastest front-wheel-drive production car in the world at launch, and the only Citroën ever built around a Maserati engine

Callout

Motor Trend's 1972 Car of the Year, the first import to win it outright

What to watch for

Two things decide whether an SM is a bargain or a bottomless pit, and neither is the paint. The first is the Maserati V6's timing gear. Three chains run the four camshafts, and the primary chain also drives the intermediate shaft feeding the hydraulic pump and alternator, so its tensioner works harder than it was designed to. Chains want adjusting every 10,000 miles, and a file with no record of the last adjustment means budgeting for the job now. Sodium-filled exhaust valves fail on engines that sit, and the oil pump quill shaft is famously thin, though a stronger replacement now exists. A full rebuild has been quoted around $13,000 plus roughly 40 hours to remove and refit it, so a tired engine reshapes the purchase. The second is the hydraulics, honest enough if served. Spheres are reckoned good for about five years, the pressure regulator and brake accumulator around six, the cylinder boots three to four. Only LHM goes in. Bodily the SM beats its reputation. Check the rear wing seams where inner and outer panels meet, magnet the lower body, and look hard at the bonded screens, which leak and rot what sits behind them. US cars lost the glass headlamp panel to federal rules, worth knowing before you fall for a photograph of a European nose.

The Story

Driving character

Nothing in the SM asks to be driven the way other cars are, and the first ten minutes are a negotiation. The brake is not a pedal in any normal sense but a mushroom-shaped button with almost no travel, metering pressure by how hard you lean on it, so the first stop puts your nose near the steering wheel. The steering is geared at two turns lock to lock, weightless at a standstill, and it fights back to centre with a will of its own, with no kickback and no road feel through the rim. Neither is intuitive. Both become second nature, and then every other car feels vague. What sits underneath all of it is the ride. The hydropneumatic suspension does not soften bumps so much as decline to acknowledge them, and the SM covers a bad French back road at a speed that feels illegal and reads as calm. The Maserati V6 is the surprise. It is not torquey and it is not loud below 3,000rpm, and then it opens up with a hard four-cam edge that has nothing French about it at all, pulling to 137mph. Because the gearbox sits ahead of the front axle and the engine entirely behind it, the SM turns in far more willingly than the weight over the nose suggests it should.

Design

Robert Opron ran Citroën's styling office and the SM is the purest thing he did there. Seen from above it is a teardrop, wide across the front track and visibly narrower at the rear, which is why the flanks look pinched from behind and taut from the front three-quarter. The nose is the argument the whole car makes: a single curved glass panel, heated, running the full width and holding six headlamps and the number plate behind it, with the inner lamps geared to the steering and the whole set hydraulically self-levelling. There is no grille, because a car this slippery did not need one. The tail does the opposite of the fashion of the period. Instead of a cut-off Kamm panel it keeps tapering, glass wrapping back to a narrow deck, and the rear wheels sit tucked well inboard of the body line. Chrome is almost absent. Published drag figures for the SM range from the mid-twenties to the mid-thirties depending on who measured and how, so the number is worth treating with suspicion, but the intent is unarguable: this was a shape drawn by airflow and by nothing else, ten years before the industry caught up.

Motorsport pedigree

The SM's competition record is short and disproportionately good. Citroën entered two in Group 4 for the 1971 Rallye du Maroc, the model's first event, over 4,350km of rutted desert track and flooded wadis. Nine of the 59 starters finished. The SM of Jean Deschaseaux and Jean Plassard won it outright, better than 26 minutes clear of a Peugeot 504. Michelin's resin wheels had been developed with exactly this kind of work in mind. The Maserati V6 then went racing without the Citroën body around it. Ligier used it in the JS2, and at the 1975 Le Mans 24 Hours the V6-engined car of Jean-Louis Lafosse and Guy Chasseuil finished second overall, one lap behind the winning Mirage GR8 of Bell and Ickx, with the race engine quoted at around 330bhp. The strangest chapter belongs to California. Jerry Hathaway's SM World campaigned a heavily modified SM at Bonneville, taking the D/BCGC record at 200.002mph in 1985. In 1987 Sylvia Hathaway qualified at 206.446mph and set the record at 202.3mph, joining the 200mph Club in a front-wheel-drive French grand tourer.

In culture

The SM's biggest role was a real one. Henri Chapron built two stretched, fully convertible Présidentielle SMs in 1972 for Georges Pompidou, with the gearing altered so they could crawl at walking pace, and the first of them made its debut carrying Queen Elizabeth II on her May 1972 state visit to France. Those two cars stayed in the presidential garage through Giscard d'Estaing and Mitterrand and were still being used for ceremony at Jacques Chirac's inauguration in 1995. Very few cars have a 23 year run as head-of-state transport. On screen the SM has been consistently cast as the car of someone slightly untrustworthy. Patrick McGoohan drove one in the 1975 Columbo episode Identity Crisis, Gerry Anderson's The Protectors ran a platinum blue example in 1971, and an SM is used in an attempted kidnapping in the 1975 Charles Bronson film Breakout. Ben Stiller gets abducted in a green one in Zoolander. Janet Jackson used a red-trimmed SM in the 1998 video for I Get Lonely. The press nickname that stuck, and the one owners still use, came from its own decade: the Concorde of the road.

Rivals

Cars from other manufacturers that competed for the same buyers when new.

Owning One

Why collectors want it

The SM is bought for its engineering, and that is unusual enough to say plainly. Most collector cars trade on beauty, speed or racing history. The SM trades on the fact that a mainstream manufacturer once spent itself into serious trouble building the most technically ambitious road car in Europe, and then had it taken away by an oil crisis and a takeover before the second act. Driving one is still the only way to feel DIRAVI steering and a Maserati quad-cam turning the front wheels through Citroën hydraulics, because nobody has attempted the combination since. The hierarchy inside the generation is real but gentle. Carburetted 2.7 manual cars are the enthusiast's pick and, being the ones people bought to drive, are often the best sorted. The fuel-injected 2.7 is the easier car to use and the one most buyers end up wanting. The 3.0 automatics built mainly for export sit at the bottom, partly because the Borg-Warner three-speed blunts an engine that wants revs, and partly because US federalisation stripped the glass nose panel and the swivelling lamps that make the front of the car work. The Chapron cabriolets and the two Présidentielle state cars trade in a different market entirely.

Which one to look for

Three factory drivetrains, and the order of preference is not the order of power. The launch car is the 2,670cc carburettor engine, 170bhp DIN through three Weber 42DCNF and a five-speed manual, and it is the SM most owners recommend: lighter over the nose than the injected car, simpler to diagnose, and the version the chassis was tuned around. From late 1972 the same 2.7 gained Bosch D-Jetronic injection for 178bhp DIN and much better manners in traffic, at the cost of extra weight and an extra system to understand. The 2,965cc engine, 180bhp DIN, went mainly to export markets tied to the Borg-Warner three-speed automatic, which is the least interesting way to use a quad-cam V6 but by some distance the easiest SM to live with in a city. Two options are worth hunting. Michelin's Résine Renforcée composite wheels, approved in July 1971 and sold from that December, are one-piece moulded resin and around 11.5 pounds lighter each than the steel wheel. Roughly 1,250 sets are thought to have been made and they were never US legal. Above the production cars sit Henri Chapron's conversions, the Mylord cabriolet and the Opéra four-door, both built in single figures, and the two Présidentielle landaulets of 1972.

2.7 Carburettor · 1970–1972

The launch specification and the one the chassis was developed around. 2,670cc quad-cam V6 fed by three Weber 42DCNF carburettors, 170bhp DIN, five-speed manual. Lighter over the front axle than the injected car and the simplest of the three to diagnose, which is why long-term owners tend to steer newcomers here.

2.7 Injection Électronique · 1972–1975

Same 2,670cc quad-cam V6 with Bosch D-Jetronic fuel injection in place of the Webers, 178bhp DIN. Cleaner running, far better tempered in traffic, and heavier at the nose. The only electronic system on the whole car, and the reason the SM does not score as fully analogue.

3.0 Automatique · 1972–1975

The 2,965cc version of the Maserati V6, 180bhp DIN, sold mainly into export markets and tied to a Borg-Warner three-speed automatic. It is the least involving way to use a quad-cam engine and comfortably the easiest SM to use in traffic, which is why so many survivors are American cars.

What owning one is like

An SM is not a difficult car to own, but it is an unforgiving one to ignore. Everything hangs off the hydraulic circuit, and the circuit rewards a calendar. Spheres go soft, the pressure regulator and brake accumulator wear, cylinder boots split and let grit into places it should not reach, and each of those is a modest job done on schedule and an expensive one done late. LHM only, changed and the system flushed, and the car simply works. The engine asks for the same discipline in a different currency. Timing chain adjustment every 10,000 miles is not optional maintenance, it is the thing standing between you and a rebuild, and the sodium-filled exhaust valves punish long storage more than they punish use. An SM that gets driven every few weeks is a happier and cheaper car than one kept as an ornament. The rest is character. You will re-learn braking and steering, and passengers will comment on both. The car rises on its haunches when you start it and settles when you shut it down, which never stops being good. Parts hunting is part of the hobby rather than an obstacle to it, and the community that has kept these cars alive since 1975 is generous with what it knows.

Upkeep & parts

Support is better than the SM's reputation suggests, though it is concentrated in a handful of places. In France the SM Club de France runs its own parts operation for members, and the Euro SM Club serves the wider continent. In Britain, SM Owners UK is the hub and Citroën Classics in Wokingham stocks classic Citroën spares including SM. In Germany Der Franzose carries hydraulic components. In North America the picture changed when SM World, Jerry Hathaway's Santa Clarita specialist and the deepest SM resource the continent had, wound down and its assets were bought by MARRS in the same town. The single most useful thing an owner has is free: the Citroën SM Wiki documents production numbers, chain tensioners, wheels and buying advice in more detail than most factory manuals manage, and the long-running Citroen-SM mailing list on groups.io answers the questions it does not. Budget honestly for two items. Hydraulic consumables on a schedule, which are cheap individually and add up, and the engine, where a full rebuild has been quoted around $13,000 before the roughly 40 hours of labour to take it out and put it back. Replica Michelin resin wheels are available if the originals have gone.