I've been a Formula 1 fan for well over a decade at this point, following the sport since 2008. As an avid motorsport and history buff, I was well aware of the legendary stints Jaguar, Ford, Ferrari, Porsche, Audi, and others had at Le Mans in the past, but I’ll admit, I only appreciated endurance racing from a distance.
That’s been changing lately. I’ve been delving deeper into the world of long-distance racing, uncovering layers of history and discovering new stories. Maybe it’s because I had the privilege of seeing the legendary Rothmans-liveried Porsche 956, the Jever 996 GT1, and the modern-day Porsche Penske 963 up close, at that Icons of Porsche event in Dubai last November, that had me hooked on Group C and World Sportscar Championship (WSC) racing.
Now, I’m no expert in the Group C category, but a quick crash course turned into a deep dive. From its early years in the 1980s to its wind-down in the mid-90s before handing the torch to the GT1 class, Group C had a cast of heavy-hitters. Porsche dominated the early chapters with the 956 and 962. Jaguar made its mark with the XJR-8, XJR-9, and XJR-14. Mazda delivered big with its rotary-powered 787B, and Peugeot left its mark literally with the WM P88’s wild 252 mph run down the Mulsanne straight at Le Mans in 1988, a record that forced the ACO to install chicanes in subsequent years, owing to safety concerns.
But among all these machines, one car in particular stood out to me: the Sauber-Mercedes C9. In 1989, it won all but one race in the World Sportscar Championship. That kind of domination demands answers. I was curious to find out what made this car so special. Why couldn’t its successors, like the C11 or the C291, replicate its success? Well, let's find out.
Group C: Motorsport Unleashed
Now, to understand the C9, you need to look back at the world it was born into. By the early 1980s, endurance racing was a tangled in a bit of a mess owing to overlapping classes and technical categories. Group 5 and Group 6 cars were fast but fragmented, and in 1982, the FIA eventually threw down a new rulebook for Group C. This concept was revolutionary: fuel efficiency became a performance metric, there were no limits on engine architecture (we’re talking turbo-flat-sixes, naturally-aspirated, rotary, turbos), ground force effect, and designers had a blank canvas for aerodynamic approaches that pushed the boundaries of physics.
The result? A wild arms race of creativity and chaos. But among these giants was a small Swiss racing outfit. A privateer with big ambitions: Sauber. Now, even before Group C began, Sauber toiled away in Group 6 with its C5 and early prototypes. When the rules finally changed in 1982, their first proper Group C car, the C6, used a dependable but uninspiring Cosworth powerplant. It finished fourth at Hockenheim in ’82 but wasn't shaking up the establishment.
The following year came the C7, this time powered by a BMW inline-six. This was better in theory, but the chassis and engine were like oil and water, technically sound but never harmonious. It finished ninth at Le Mans in ‘83, its high point. Sauber sold off the lone C7 to a private team and hit pause for 1984. That was a bold but smart decision. They needed an engine partner for the 1985 season.
Enter: Mercedes-Benz. Now the German automaker had unfinished business in top-tier racing. The heroics and lineage of the silver arrows can be traced to the pre-war days, but even in the post-war era, they had dominated Grand Prix racing in the 1950s before disappearing altogether, after the horrific crash at Le Mans in 1955. Sure, the brand remained active in touring and rally events, but it avoided top-tier motorsport for decades. But by the mid-1980s, they quietly eyed a return.
Mercedes had the hardware, a 5.0-liter twin-turbocharged V8 designed for Group C, but no team or chassis to run it. Sauber, as previously mentioned, was in search of an engine. So in 1985, the two joined forces, and the result was the C8.
On paper, the C8 looked like a winner. However, the car qualified a lowly 17th at Le Mans, then crashed out during the race. Worse, it never even started another race in the ‘85 season. While its showing wasn’t as expected, this was a minor setback, because the breakthrough that Sauber needed would finally come in 1986.
With new sponsorship from Kouros (yes, the cologne), the team rebranded as Kouros Racing for 1986. They stuck with the C8 and kept pushing. The result? A landmark win at the 1000km of Nürburgring (GP-Strecke), with Henri Pescarolo and Mike Thackwell taming the Nordschleife. This marked Sauber’s first Group C victory and proved they could run with the big guys and works teams.
Sauber-Mercedes C9: The Monster Emerges
In 1987, the team rolled out the next iteration: the Kouros Sauber-Mercedes C9. Underneath, it was still closely related to the C8, but Sauber reinforced the aluminum monocoque, improved aerodynamics, and fitted new triple-K turbos to Mercedes’ V8. The result was a lighter, stiffer, far more potent machine with around 800 horsepower on tap, in qualifying mode.
But 1987 wasn’t a breakout season. Two DNFs, a lone points finish at Spa, and an embarrassing Le Mans retirement due to gearbox failure made one thing clear: the car was fast, but fragile. Reliability was a major concern, and Kouros Racing eventually pulled the plug.
But instead of folding, Mercedes itself stepped up and in 1988, and the team returned as Sauber-Mercedes, this time backed directly by Daimler and racing under AEG-Olympia’s black-and-green livery. The C9 got crucial upgrades: relocated radiators to the nose for better airflow, a redesigned rear wing mounted to a central support increasing volume for ground effects, horizontal dampers, and improved turbos.
This led to five wins that season, one shy of Jaguar’s title-winning NA V12-powered XJR-9, but enough to make a statement. The C9 was no longer just quick, but it could survive and compete in long-distance racing with better reliability. The only thing missing: Le Mans. Though not part of the championship, it was the crown jewel and the primary target for the three-pointed star.
In 1989, Mercedes doubled down, and the M119HL V8 engine was overhauled with aluminum heads and extra boost for the turbos, now pushing 820 horsepower and 579 pound-feet of torque. But only revving to 7,000 rpm, the stress on the engine was low, and this vastly improved reliability. This, coupled with a flatter torque curve, made it flexible for varying racing conditions, be it for sprint races or long-distance endurance racing.
Even in the pre-carbon era, the C9 only weighed 905 kilograms (1,995 pounds). Power-to-weight was off the charts. For some context, the power-to-weight ratio (0.411 hp/lb) was about half that of modern-day F1 cars, but the downforce figures were comparable, 4,000 to 5,000 pounds at speed. With full factory support and the return of the iconic Silver Arrows livery, the C9 launched into a dominant season. It won seven of eight World Championship races that year, only missing out at Dijon in France, due to Michelin tire issues in extreme heat.
At Le Mans that year, Mercedes entered three C9s. In qualifying, the #61 car clocked a staggering 400 km/h (248 mph) on the Mulsanne Straight, one of the highest speeds ever recorded in closed-circuit racing. But it was the # 63 car, driven by Mass, Reuter, and Dickens, that charged from 11th on the grid to win the race. Mercedes finished 1-2-5.
Mercedes pulled the plug and pivoted toward Formula 1
The C9 was the car that reminded the world what Mercedes could do when it wanted to dominate. It proved they hadn’t forgotten how to win even after being away from top-tier motorsports for over three decades. It was a brief but blinding moment in the motorsport universe. Mercedes, haunted by its past and consumed by an obsessive pursuit of dominance, and, almost as suddenly as it had arrived, it vanished again.
The C11 that followed may have been quicker, and the C291 more radical, but amid changes in regulations and an even greater degree of overlap with Formula 1, neither could replicate the success of the C9, and Mercedes formally ended its factory Group C program in 1991.
Today, you can still watch grainy footage from the 1980s and 1990s to marvel at the C9’s achievements, or you can see one sitting at the Mercedes Museum in Stuttgart. It was exhibited earlier this year May, at the FuoriConcorso, part of the greater Villa d’Este weekend on the shores of Lake Como in Italy.
But to truly feel it, you’d want to see it at full chat at a place like Goodwood. While this year’s event was all about 75 years of Formula 1, the C9 was last seen at the British Hill Climb in 2024. Classic recreations and historic Group C races also present another opportunity. Only six chassis were ever made between 1987 and 1989, and like anything with so much pedigree and provenance, these cars now command top dollar; you’re looking at well north of $5 million a piece.
We’re just a few weeks out from the Monterey Car Week, and we have a special feature film set to screen on a single-commission 1,000 horsepower Mercedes unicorn. While it has nothing to do with the Sauber C9, what the two cars do have in common besides a three-pointed star on the nose, is a V8 heart and silver livery. Watch this space.
