Mercedes-Benz C111

The Mercedes-Benz C111 was a series of experimental automobiles produced by Daimler-Benz in the 1960s and 1970s, used as a rolling testbed for new engine technology. The first version was completed in 1969 and shown at the Frankfurt motor show that year, with a fiberglass body and a mid-mounted three-rotor Wankel engine, and a four-rotor version followed in 1970. The company then chose not to adopt the Wankel and turned to turbocharged diesel engines for the second and third cars. The C111 III of 1978 had a drag coefficient of 0.195 and reached 338 kilometres per hour at the Nardo Ring, and the C111 IV with a twin-turbocharged V8 averaged 403.78 kilometres per hour there in 1979. Other experimental features included multi-link rear suspension, gull-wing doors and a leather interior with air conditioning. Sixteen cars were built in total, and the series inspired the Mercedes-Benz Vision One-Eleven of 2023.