K-wagon (comb wagon)

K3 comb car based on a Mercedes-Benz 170 V.

Tubular frame (black) with body skeleton (light) of a replica of the K4 Kamm car at Techno-Classica 2007

The K-Wagen (Kamm-Wagen) is a fuel-efficient research car developed by Wunibald Kamm with a low-drag design, four of which were manufactured at the Research Institute for Automotive Engineering and Vehicle Engines Stuttgart (FKFS) in the years 1938–1941. The vehicles had a semi-teardrop-shaped profile with a shortened rear (so-called K-rear ) and a clear lateral rear indentation. In addition to the aerodynamic features with drag coefficients down to 0.23 (series vehicles at that time had values ​​around 0.5 to 0.6), the following should be mentioned:

• automatic tire pressure adjustment (to reduce rolling resistance)
• Overdrive (lower engine speed to reduce consumption)
• Mixture leaning of the engines at motorway speed (also to reduce consumption)

The best known Kamm car, also the one with the cheapest value of 0.23, was the BMW K1 from 1938/39; The basis was a pre-series chassis from the BMW 335 . The BMW K4 from 1939/40 was also based on the BMW 335 . ${\displaystyle c_{w}}$

Web links

Commons : Comb Carriage  - collection of images, videos and audio files

• Photo of the K1 car ( BMW K1 ) on the FKFS website , accessed on March 25, 2010
• Pictures and backgrounds of the BMW K1 , BMW K4 and the BMW Kamm models in general on the website of BMW-classic.de under “BMW history” → “ Image search” → “BMW K4”, “BMW K1 Kamm” (8 photos each ) or “BMW Kamm” as well as under “BMW History” → “Search in the BMW Group Archive” → “BMW K4”, “BMW K1 Kamm” (8 photos each) or “BMW Kamm”, accessed on March 25, 2010