Mercedes-Benz C-111 (Germany, 1969)

At the Frankfurt International Motor Show (IAA) in September 1969, Mercedes-Benz presented an out-of-the-ordinary car: the C 111.

This “test lab on wheels” wore a wedge-shaped body and upward-opening gullwing doors. The color was an orange metallic, originally designated “rosé wine”. The body consisted of fibreglass-reinforced plastic and was riveted and bonded to the steel frame-floor unit.

The C 111 served to test the Wankel engine. A three-rotor unit developing 206 kW (280 hp) provided the propulsion power and permitted a top speed of 260 km/h (162 mph). Just a few months later a thoroughly revised version of the C 111 was shown at the Geneva Motor Show. It featured a four-rotor Wankel engine with an output of 257 kW (350 hp). The car accelerated from standstill to 100 km/h (62 mph) in 4.8 seconds and attained a top speed of 300 km/h (186 mph).

Little more was heard about the Wankel engine; diesel technology now became the focus of research. In June 1976, April 1978 and May 1979, the C 111 completed runs on the high-speed test track in Nardo in southern Italy, which produced several absolute world records over various distances.

On the first record run, the C 111-II D, almost unchanged on the outside in comparison with 1970, was powered by a thoroughly revised five-cylinder diesel engine displacing 3.0 litres; instead of the 59 kW (80 hp) of the production car it now developed 140 kW (190 hp).

In 1978, the C 111-III developed an output of 169 kW (230 hp) with an additional intercooler. But this car now had little in common with the original C 111. The silver-coloured body mounted on a floor unit with changed dimensions was even more thoroughly streamlined.

The C 111-IV of 1979 came with further aerodynamic refinements, additionally featuring distinctive spoilers, a changed front end and two tail fins. Its propulsion unit was a 4.5 litre V8 engine from regular production, enlarged to displace 4.8 litres and generate 367 kW (500 hp).