Mercedes-Benz C111-II D
The C111 was a series of experimental automobiles produced by Mercedes-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 gullwing doors and a luxurious interior with leather trim and air conditioning.
A certain sluggishness has been accepted as an intrinsic characteristic of the diesel engine ever since Mercedes-Benz installed one in the world's first diesel passenger car in 1936. So wrong, some 40 years later, engineers working for the Swabian manufacturer began to look more closely at the performance potential of the thrifty compression-ignition engine - and soon discovered what they were looking for. They fitted a turbocharger to the standard 80 hp five-cylinder engine found in the 240 D 3.0 and 300 D models to elicit an impressive 190 hp from the 3-litre diesel.
With this powerful diesel engine under the bonnet of a spectacularly styled gull-wing model, painted in bright orange, Mercedes-Benz was soon geared up for some record-breaking drives. The C 111-II D powered its way to some sensational records at the Nardo circuit in southern Italy in 1976. For a whole hour, for example, it circled the high-speed track at an average speed of 253.770 km/h. It went on to collect further records in all categories – over distances of 10 to 10,000 kilometers and over periods of 6 to 24 hours.
Source: Mercedes-Benz press and Wikipedia, 2011