This is the Citroën SM Story.
André Citroën, the company’s founder, had always envisioned a flagship car and Citroën’s first attempt, the 22CV Traction Avant was nearly released in 1934, just one year before his tragic death. But all thoughts of high-end cars went by the wayside with the Second World War and subsequent restructuring, and by 1960 Citroën was in financial difficulties. But thanks to its line-up of the 2CV, Ami range and the phenomenal DS, the company soon found itself back in the black.
They were selling 1¼M cars a year with a 30% market share in their native France. So, thoughts turned to expanding their range. The DS was a landmark car, but it was a family runabout. Citroën initially wanted to make something sportier and started “Project S” in 1961. The DS would be the starting point for the new car and Citroën knew they needed to tackle two things – the handling and the engine. The DS used an innovative form of hydropneumatic suspension. When the car goes over a bump, instead of using springs and dampers, it uses a combination of a ball of nitrogen gas and pressurised fluid to soak up the bump. As the car already has pressurised fluid for the brakes, the suspension system uses the same system. This gave a very smooth, limousine-like ride on the DS, but it wallowed a little through the corners – not good for the sporty “Project S”. So, Citroën worked to make the car go flat through corners by pumping hydraulic fluid to the side feeling the most force. The photo on the left and right are taken at the same speed going through the same corner. With the levelling system active the car on the right looks like it’s not even going through a corner! The work done here improved Citroën’s suspension setup for the Citroën SM, but they weren’t able to perfect flat cornering until the Xantia Activa in 1994.
But the hydropneumatic suspension had a party trick that it could be raised high to allow for high ground clearance or to allow one wheel to be changed without a jack or driven with only three wheels in an emergency. With the handling improved, thoughts turned to the engine. A fast, sporty car needed more power than Citroën’s own 4-cylinder engines could produce, so they worked on creating their own 6-cylinder engine but with their limited resources couldn’t make a design that worked.
Being a company that embraced new technology, they started work on a Wankel rotary engine, but it wouldn’t be ready for the new car, and in fact Citroën could never get it ready for production, abandoning it in the early 70’s. By this time the project had morphed from making a hot DS to a high-end luxury car that would make André Citroën proud.
Germany had Mercedes, England had Jaguar, and the USA had Cadillac. National pride determined that France needed its own luxury car. The hydraulic fluid wouldn’t just power the brakes and suspension. Citroën had been working on an innovative power steering system with self-centering that they called “DIRAVI” that stood for “Direction à rappel asservi” or “Steering with controlled return”. In the UK it was sold as “Varipower” and in the US as the slightly creepy “SpeedFeel”. Mmmm! Speedfeel! It was the first commercially available variable assisted power steering system, giving more assistance at low speeds with just two turns lock to lock. The car would get the DS’s innovative front lights that turned as you went around a corner to allow a clear view of the road ahead. But these lights would also be self-levelling. US customers had to do without this feature as movable headlights were banned in the USA.
The car would have a long teardrop shape that divided opinion, but the teardrop was used to give it a low drag coefficient of just 0.26. That’s not just impressive at a time where the Mercedes 280SE had a drag of 0.45, but even today where the much more modern Audi A6 manages a drag factor of just 0.27. Citroën was again ahead of conventional car makers who would only start chasing low drag factors in the early 80’s. They’d realised lower drag meant a faster car guzzling less fuel.
The new car would have a cut-off rear, called a Kamm tail, similar to modern cars like the 1996 Honda Insight or Toyota Prius, cars that were also chasing a low drag factor. By the late 60’s the car was coming together, but they still hadn’t found the right engine for their new car. They found it at Maserati, and specifically the lightweight aluminium DOHC V8 from the forthcoming Maserati Indy. In fact, Citroën liked the V8 so much, the bought the whole company, just like Victor Kiam and those cheesy 80’s Remington razor adverts (“so impressed, I bought the company”). But Citroën’s main market, France, had a tax that heavily punished cars over 2.8L, and Maserati’s V8 started at 4.2L. With time running out a panicked Citroën gave Maserati just 6-months to lop off two cylinders and deliver them a V6. The Maserati engineers were appalled by the demands and hit back at the French car company, but cooler heads prevailed, and a rough engine was ready in just a few weeks! The car would use a 5-speed manual gearbox, the first time Citroën had offered 5 speeds.
At launch there would be no automatic, but later a three-speed automatic would appear to appease North American customers. To save further weight, the car used carbon-reinforced resin wheels, a forerunner of carbon fibre wheels we use today. The combination of low drag, V6 engine and weight savings allowed this big car to get to 60mph or 100km/h in seconds, with a top speed of 137mph or 220km/h. A fast car needs good brakes to stop, and the SM would have high performance disc brakes that had one of the best stopping distances of any car at that time. But they wouldn’t be operated by a normal brake pedal. Oh no! This was Citroën. Maybe it was the 1960’s magic mushrooms, but the SM had a mushroom-like button in place of a brake pedal that had very little travel. Citroën wasn’t done with innovative features. Years before it became a feature on most cars, the SM introduced rain-sensing windscreen wipers.
Instead of using a water sensor, the wipers would detect the electrical current needed to move the wipers. Less current meant less friction which meant more rain which told the wipers to move faster. The SM was launched in Geneva in the spring of 1970. It came second for “Car of the year”, pipped by Citroën’s own GS that had been introduced the same year. And in the USA, Motor Trend named it their car of the year in 1972. The press loved its smooth ride and handling, modern interior and innovative features like the lights, but found it difficult to drive smoothly with over-sensitive steering at high speeds and the limited travel brake, and they decried the cramped cabin in the back and poor visibility. But the SM’s main problem was its price. It cost the same as a BMW CS, Mercedes 350SLC, Porsche 911 or Ferrari V6 Dino 246, and was more expensive than a Cadillac. Citroën wanted to compete with cars like the new Jaguar XJ6, but the Jag started at £1,800 in the UK, whereas the SM cost a whopping £5,200. And Citroën didn’t even put the steering wheel on the right side of the car, leaving that to enterprising UK and Australian dealers to do their own hand-built conversions.
Another problem was the learning curve. The car felt different with its odd suspension, and the brakes didn’t inspire confidence with its limited travel. After a confusing test drive, it’s easy to see customers being drawn to competitors’ cars that were more familiar. It’s true that Tesla have a similar problem today, but there’s a halo of “cool” around a Tesla that Citroën simply didn’t have at the time. It was fast, but due to the size-limited 2.8L engine it was beaten by the competition. Citroën improved the engine in 1972 by switching out the triple Weber carburettors for Bosch electronic fuel injection. This not only gave it better acceleration, but also produced a better cold start and helped it deal with the new US and European anti-pollution regulations. They also produced a more powerful 3.0L variant in 1973 with a top speed of over 140mph or 225km/h. Although it’s hard to believe for such a boat of a car, but the SM was entered in the gruelling 1971 Morocco Rally.
What’s more surprising was it won! After the launch, customers found that there were issues with the engine. It was shorn from a 90° V8, but 90° for a V6 isn’t ideal. It would vibrate excessively at idle and in general sounded rough. Not ideal for a luxury car. To add to this, it wasn’t the most reliable engine and Citroën were far from sympathetic, further eroding buyer confidence.
The rich and famous were drawn to its odd beauty, as well as world leaders like Soviet leader Leonid Brezhnev and of course many French presidents who used the open top “Presential” variant to drive around with visiting dignitaries. Even the Pope got in on the act before his famous Popemobile. The SM was never going to be a high selling car at the price it was offered at, and not only having problems with the 1973 oil crisis, it was dealt a big blow in 1974. Citroën believed that they’d got an exemption from impending US bumper legislation, but at the last minute they learnt this wasn’t going to happen.
This blocked their main export market, as the changes to put larger bumpers were extensive and expensive for such a low volume car. The remaining US SMs were put on a boat to be sold in Japan. Without the SM’s largest export market, the going would be tough, but then a bankrupt Citroën threw in the towel. With no more money the company couldn’t afford to keep production going, so the last SM rolled of the production line in 1975. Citroën merged with Peugeot in 1976 and all thoughts of large luxury cars went out of the window. But the SM legacy is far reaching. Progressive self-centering power steering is commonplace today, although it uses motors rather than hydraulics. Mercedes have used hydraulic suspension almost as long as Citroën has, and it’s still available on the S-Class as “Magic Body Control”.
Mmmm Magic Body Control… Even Rolls Royce licensed Citroën’s self-levelling suspension, it was that good.