Mercedes-Benz C111. World's Fastest Experiment.

Introduction

It was the year 1969, in Stuttgart, Germany, the little town Daimler calls home. Rumors were circulating the German community living there that Mercedes-Benz were developing a top secret experimental car with innovations that could potentially turn the entire industry upside-down. The German public were anticipating the launch of such a mysterious car, designed with so many breakthroughs in mind that it would look like as if it had came from the future, and would place the brand at a massive advantage compared to the competition at the time.

The IAA soon was held in Frankfurt, Germany, during the same year. Automakers from all around the globe flocked to the Messe Frankfurt convention center, to show off their products and offerings to many, many potential customers. Some of the more important debutants during that show were Audi’s well known 100 Coupe, a fastback shaped 2 door. But the most anticipated car to the German public, the car that would break all expectations and lead the way in automotive innovation, was the Mercedes-Benz C111-I.

Debut

journalists and attendees flocked to the Mercedes-Benz stand to see this magnificent and futuristic piece of automotive innovation. Cameras and notepads in hand, flashes from left right and center bounced off the car’s aerodynamic and streamlined glass-fiber bright orange bodywork, as journalists tried to take photos of the magnificent machine. They also scribbled down notes on the car’s forward-thinking technologies, such as the Wankel Rotary Engine, the brainchild of Felix Wankel, along with gullwing doors which opened upwards to greet the skies, along with a multi-link rear suspension for improved handling.

It was clear to Mercedes-Benz and their hard working development team that all those years of research, design and testing had paid off after that successful debut during the Frankfurt Motor Show. Originally, they never intended to create a successor to the iconic 1930 Mercedes-Benz 300 SL. The only similarities those two cars had were its gullwing doors, hinting at the public eye that this was intended to be a successor to the 300 SL.

The C111-I

The C111-I was purely intended to become an experimental vehicle for the brand, a benchmark for their innovations and their development in the years to come. The C111’s bodywork was meant to become a testbed for future Mercedes-Benz bodywork and panels for future models, experimenting with the use of fiberglass and aerodynamic design for efficiency, speed, weight savings, and rigidity. The car was also meant to become a testbed for Mercedes-Benz engines, more specifically, the use and application of Felix Wankel’s rotary-piston engine.

The car wasn’t only used to experiment with technical features. It also experimented with features that would benefit the driver, such as a luxurious leather interior, along with air conditioning. Air conditioned cars were rare back in the 1960s, so this was a clear indication of forward thinking minds at work, along with bringing massive potential the techonology would bring to the brand, along with making a heavy, heavy impact on the future of automobile technologies. It was also rumored the C111 could reach 300 km/h or 180 mph flat out.

Problems and Doubt

Unfortunately for Mercedes-Benz, the C111 was far from ideal to be put into a series production car. Due to the unreliability and doubts plaguing the Wankel Rotary-Piston engine, Daimler decided not to put the car into production. The innovation still was new at the time, so many doubts clouded the mind of development, as they had not done enough testing and research into this newly introduced technology. The Rotary engine was also very inefficient compared to a conventional piston engine. The car’s circumstances also did not help at all, as the car was developed during the Arabian Oil Embargo of 1973. Prices of crude oil worldwide had skyrocketed. Sales of cars were reduced to near-zero, and sales of high-performance vehicles at the time basically came to a standing halt. It would be a very, very unwise decision to produce the car, as practically no one would buy it.

Safety standards for automobiles were also highered with tighter restrictions put in place, along with bigger penalties to automakers who fail to meet standards. The C111-I’s fiberglass body panels, along with its plastic and composite construction were more prone to crumbling and were more unsafe compared to a conventional steel alloy construction. This was a massive letdown to all the people who were looking forward to the car’s production. The car was so anticipated by the German public, that even a very, very dedicated fan of Mercedes-Benz actually submitted an order with a bank cheque and is willing to pay every single penny in order to see that magnificent machine parked in his driveway.

The C111-II D

It might look like the end of the line for the C111 program to Mercedes-Benz, but every dark cloud has a silver lining. Because the C111 could not be produced or driven on the road, the development team re-purposed it to become a record-setting car on test tracks around Europe, showing the European public what Mercedes-Benz is capable of. The oil embargo was also going on in the background, so automakers were looking for more efficient solutions for their engines, giving the diesel engine a massive opportunity. The C111 abandoned its Rotary engine and replaced it with a conventional Diesel compression engine, specially developed to prove the world that combustion engines were not loud and lacking dynamism.

As a result, The C111-II D was born, powered by a three liter, straight-five cylinder engine block producing 190 horsepower, based on the OM617 engine engine powering the W115 E-Class. Its aerodynamic features had also been improved, bringing down the car’s drag coefficient all the way to under 0.25. It was ready to break records around the globe, just like its spiritual ancestor, the Mercedes-Benz W125 Rekordwagen.

Record Setter

In the year 1976, Mercedes-Benz set to the unforgiving Nardo proving ground in Italy. It might sound easy to just drive around fast in a constant circuit, but at high speed, the phrase “margin for error” does not apply at all. Add the fact that safety standards were not as good as today, the chances of an accident at high speed were high, while the chances of surviving that accident is low. Those fears did not stop Mercedes-Benz from trying. They spent hours and hours of hard work and labor developing this car for one purpose, a record breaker, and they are not going to put all that time and manpower to waste…

The C111-II D shattered expectations and put out an outstanding performance at Nardo, with four brave test drivers setting sixteen world records, 13 of them being records for diesel vehicles, and the remaining three being records for any car with any type of engine. They broke the record for the worlds fastest car, with a clocked speed of 252 km/h, or 156 mph. Those records that were achieved by Mercedes-Benz put all negative perceptions of the diesel engine to rest, proving what it could do at its maximum potential.

The C111-III

It looked like Mercedes-Benz had reached the absolute limit with the C111-II D, shattering 16 records in one test run. But the development team thought they could go even further.
That motivation gave birth to the Mercedes-Benz C111-III, the third iteration of the C111 experimental car. The body had gone through a massive overhaul, with a more streamlined design featuring a sharkfin, with panels covering the wheels for the sake of aerodynamic efficiency, bringing the car’s drag coefficient lower to 0.191. The car’s engine had also been upgraded, squeezing more power out of the OM617 engine from 190 horsepower all the way up to 230 horsepower.

Mercedes-Benz returned to the Nardo proving ground, and came back stronger than ever. With a more powerful car featuring a lighter and more aerodynamic body, it was just screaming to the people that records will be broken today. The C 111-III went on to break nine world records in 1978, including shattering their previous speed record, with a clocked speed of 200 mph.

The C111-IIII/C111-III V8

After shattering nine records at Nardo, Mercedes-Benz and their development team decided to give the C111 program one last hurrah with the C111-IIII, the fourth and final iteration of the C111 experimental cars.

The C111-IIII featured a completely new engine, built from the ground up, now featuring a twin-turbocharged V8 instead of reusing the 5-cylinder engine found in previous iterations, now producing an absurd 500 horsepower, a huge leap compared to the C111-III’s 230 horsepower. Its body has also been optimized and tweaked for even less drag coefficient, with a new rear wing and a modified front section with a massive splitter installed combined with the use of lighter materials for a higher top speed.

On May 5 1979, Mercedes-Benz returned to Nardo for one last time. They would proceed to break all expectations the public had on the program, shattering their speed record by a huge margin. The C111-IIII broke the top speed record, with a clocked speed of 404 km/h or 251 mph, achieved by Hans Leibold in one run which lasted a minute and 57 seconds. That speed record would remain untouched for years to come…

Public Reception

Car journalists and enthusiasts alike praised the C111 for its forward-thinking innovations, such as the application of the Wankel rotary engine, gullwing doors, along with its blisteringly fast top speed and style. Some notable receptions were from Autocar magazine and Austrian newspaper Linzer Volksblatt.

Autocar magazine called the car a “sensation.” They also commented that as a result of that car, the entire auto industry was “dumbstruck, as the press couldn’t get enough of it and the public were bowled over.” Not long after, in the spring of 1970, after Mercedes-Benz unveiled the C111-II, Autocar commented that the car “quickly became the unrivaled dream car of an entire generation.” Linzer Volksblatt called the C111 a “Rotary Torpedo” and says that it “epitomises the special inventiveness and passion of the Mercedes-Benz designers and engineers.”

Successor to the C111

In the year 1991, Mercedes-Benz unveiled a successor to the C111 program, the C112. The C112 was meant to be a road legal version of the C11 racecar. The car was equipped with a M120 V12 engine, with peak power of 402 hp and 580nm of torque, linked to a 6-speed manual transmission. The body was built by Italian coach builder Carrozzeria Coggiolo, combined with a chassis supplied by Mercedes-Benz.

At that time, pop up headlights were common in sports cars, but Mercedes-Benz decided to use two fixed lights on the car, as pop up headlights increased drag and created aerodynamic turbulence. The car had an electronically controlled front splitter, along with gullwing doors just like its predecessor, and as a nod to the iconic 300SL. A smooth aerodynamic body along with the use of wing mirrors mounted of the A-pillar gave the car a drag co-efficient of 0.30, the lowest ever on a sports car at that time. The front spoiler and the rear wing controlled the lift generated due to the low drag coefficient.

Unfortunately, after 700 deposits made by customers, the car never saw the light of day.

But another car would avenge the C111, a car with a lot more power and technology equipped, along with a more aerodynamically advanced and lightweight body, powered by an engine straight out of a Formula 1 car…

The Mercedes-AMG Project One.