The Mercedes-Benz C111 was a series of experimental automobiles produced by Daimler-Benz in the 1960s and 1970s. The company was experimenting with new engine technologies, including Wankel engines, diesel engines, and turbochargers, and used the basic C111 platform as a testbed. Other experimental features included multi-link rear suspension, gull-wing doors and a luxurious interior with leather trim and air conditioning.
History
The first version of the C111 was completed in 1969, and presented at the 1969 IAA in Frankfurt. The car used a fiberglass body shell and with a mid-mounted three-rotor direct fuel injected Wankel engine (code named M950F). The next C111 appeared in 1970; it was shown at the 1970 Geneva International Motor Show. It used a four-rotor engine producing 260 kW.[1] The car reportedly could reach a speed of 300 km/h.[4]
The company decided not to adopt the Wankel engine and turned to diesel experiments for the second and third C111s. The C111-IID's engine was a Mercedes-Benz OM 617, and produced 140 kW at 4200 min−1. It was based on the Mercedes-Benz 85 kW variant of the OM 617 used in the Mercedes-Benz W 116 S-Class, but had a different turbocharger without a wastegate, which allowed an increased pressure ratio of 3.3. Daimler-Benz also added an intercooler that significantly improved the engine's thermal efficiency.[2]
The C111 III prototype that was completed in 1978, had a more aerodynamic bodywork that gave it an air drag coefficient of 0.195. It had a modified 3-litre version of the Mercedes-Benz OM 617 five-cylinder Diesel, now producing 170 kW, and a BMEP of 1.68 MPa, resulting in a maximum torque of 401 N·m at 3600 min−1. It enabled the C111 III to reach a top speed of 338 km/h at the 12.5 km long[5] Nardò Ring in 1978, and also to average a 16 l/100 km fuel consumption at an average speed of 325 km/h.[6] The engine was fitted with an M-type inline injection pump of Bosch's PE series with a maximum injection pressure of 40 MPa.[7]
The C111 IV had a 4.5 L twin KKK-turbocharged V8 engine that produced 368 kW at 6000/min.[3] This set another record at the Nardò Ring in 1979, with an average speed of 403.78 km/h (250.958 mph), driven by Hans Liebold.[8]
Total production was 16 cars: 13 first and second generation Wankel engined cars, two diesel engined third generation cars used in the Nardò record attempt, and a single V8 engined fourth generation car.[9]
Mercedes-Benz introduced the C112 at the Frankfurt Motor Show in 1991 as a proposed production sports car. The car used a mid-mounted 6.0 L V12 engine. After accepting 700 deposits, the company decided not to proceed with production.
External links
- Mercedes-Benz C 111
- eMercedesBenz Feature: A Look Back At The Mercedes-Benz C 111 Research Vehicle July 31, 2008
References
- Wolf-Dieter Bensinger. Rotationskolben-Verbrennungsmotoren Springer, 1973^
- K. Zinner. Aufladung von Verbrennungsmotoren Springer-Verlag, 1980^
- Lilly Wöbcke Andreas Of-Allinger. 50 Jahre Mercedes C111: Design-Studie mit Wankelmotor auto motor und sport, 2020-03-20, retrieved 2023-11-26^
- Mercedes-Benz C 111. www.mercedes-benz.com^
- Porsche buys Nardo test track Top Gear, 12 April 2012, retrieved 18 August 2014^
- Konrad Reif. Klassische Diesel-Einspritzsysteme Springer, 2012-02-23^
- Konrad Reif. Klassische Diesel-Einspritzsysteme Springer, 2012-02-23^
- Storia - Nardò Technical Center Home - Nardò Technical Center, retrieved 2019-07-06^
- 1970 Mercedes-Benz C111-II - Jay Leno's Garage^