If you ever wondered what happens when Mercedes-Benz decides to go completely mad, in a good way, meet the C111. No, it wasn’t a production car. No, you could’t buy one. And yes, people actually sent blank cheques to Stuttgart begging for it. That’s how bonkers this thing was. But it wasn’t just one car, Mercedes-Benz used the C111 for several different versions.
Imagine a car that looks like it was designed by a sci-fi illustrator on espresso. The C111 cars all had gullwing doors, a fiberglass wedge-shaped body, and a paint job called Weissherbst metallic orange.
These photos were taken in 2019 when Mercedes-Benz made a big impact during the 2019 Techno Classica show in Essen, Germany. They brought 5 of these so-called C111 cars to the show. The Techno Classica show is the largest classic car show in Europe and exhibitors include car manufacturers, dealers, restoration companies and private collectors. One of the big changes, and something that has been going on for a few years now, is diminishing support from the big three German car manufacturers. So you won’t see these kind of exhibitions anytime soon at a car show.
This Designstudie SLX from 1966 was the brainchild of Paul Bracq, Mercedes-Benz’s legendary chief stylist, and Giorgio Battistella, a fresh recruit from Italian design house OSI. Their goal? To create a mid-engined halo car that would rival the likes of the Ford GT40 and the newly unveiled Lamborghini Miura.
Unfortunately, the SLX never made it past the concept phase. When Fritz Nallinger, head of R&D, retired in 1965, his successor Hans Scherenberg hit the brakes on all ongoing projects. The SLX didn’t survive the review. The board wasn’t convinced, and Mercedes returned to its comfort zone of sedans and front-engined coupes.
Though the SLX was shelved, its spirit lived on. It laid the groundwork for the C111 experimental series.
Unveiled in 1969, the C111-I wasn’t just a concept, it was a rolling test lab, designed to push the boundaries of engineering, design, and performance. And it did so with flair.
At the core of the C111-I was a three-rotor Wankel engine, a compact, high-revving marvel that produced 280 bhp and could scream up to 7000 rpm. It was smooth, quiet, and unlike anything Mercedes had ever built.
Paired with a ZF 5-speed manual, limited-slip diff, and a triple-plate clutch, the C111-I could rocket from 0–100 km/h in 5 seconds and hit a top speed of 260 km/h. Not bad for a car made of fiberglass-reinforced plastic.
Shortly after the release of the C111-I, the development continued as the company unveiled the C111-II in 1970. The C111-II was powered by a 4-rotor Wankel engine, a rotary setup that sounded like a chainsaw on Red Bull. It churned out 349 horsepower, revved to 6000 rpm, and could launch the car from 0–100 km/h in 4.8 seconds. Top speed? A blistering 300 km/h.
That’s supercar territory in 1970.
The earlier C111 prototypes were all about Wankel rotary engines, exotic, high-revving, and ultimately unreliable. So Mercedes pivoted. The C111-II D was powered by a 3.0-liter inline-five turbocharged diesel, based on the OM617 engine found in your grandma’s 300 D. It was Mercedes-Benz’s bold response to the 1973 oil crisis.
But this wasn’t your average diesel. It had a turbocharger, a massive intercooler and enough boost to make a rally car blush. The result? 190 horsepower, 392 Nm of torque, and a top speed of 300 km/h. In a diesel. In 1976.
By 1979, Mercedes-Benz had had enough of playing nice. The rotary engines were shelved, the diesel experiments had smashed endurance records, and now it was time to go fast. Not just fast but record-breaking fast. Enter the C111-IV Rekordwagen. A sleek, silver, single-seat missile designed for one purpose: obliterate the world speed record. And it did. Spectacularly.
Forget diesel. Forget rotary. The C111-IV packed a 4.8-liter twin-turbocharged V8, based on the M117 block. It had: 500 horsepower and 600 Nm of torque.
So there you have it, the C111 series: a mad, magnificent parade of gullwing dreams, rotary screams, diesel miracles, and turbocharged record-breakers. These weren’t just concept cars; they were engineering flexes, rolling science experiments, and speed-fueled fever dreams from a company that usually builds luxury saloons and bulletproof taxis.
From the rotary-powered rebellion of the C111-I to the diesel-defying C111-II D, and finally the silver streak of the C111-IV smashing past 400 km/h, Mercedes-Benz didn’t just flirt with the future, they took it out for a joyride, broke a few records, and left the rest of the world wondering what just happened. And while none of these machines ever made it to your driveway, they made it into the history books.