| petrol | |
| diesel | |
| alcohol based | |
| gas (LPG, CNG) | |
| steam | |
| electricity |

Series: Tropfenwagen
The Rumpler was a car developed by Austrian engineer Edmund Rumpler.
Rumpler, born in Vienna, was a designer of airplanes when in 1921 he introduced the Tropfenwagen on the Berlin car show. It was to be the first streamline car (beating the American Chrysler Airflow and Czech Tatra T107). The car featured a mid-engine layout, with a W6 engine. It had three banks of paired cylinders, all working on a common crankshaft. Around 80 cars were built. It was found to have a CW-value of only 0.28. Rumpler was the person who patented the swing axle suspension design, as well as the tranasaxle. The transaxle was used in some of the most significant vehicles of the 20th Century : the Mini, the VW Beetle, the Porsche 356 and 911 among others.
The test, which was run at a Volkswagen windtunnel in 1979, surprised engineers of the day. Volkswagen wouldn't beat the value until 1988 with the Passat.
2-door 4-seat W6 12v 2.6L OHV M-3 26.8 kW / 35.9 hp / 35.9 hp | Rumpler Tropfenwagen (1921) |