Kammback

A Kammback is a car body style that derives from the research of the German aerodynamicist Wunibald Kamm in the 1930s. The design calls for a body with smooth contours that continues to a tail that is abruptly cut off. This shape reduces the air resistance of the vehicle. "Kammback" is an American term. In Europe the design is generally known as a Kamm tail or K-tail.

The earliest use of "Kamm" to describe an automobile body incorporating this design was the prototype 1940 'Kamm' Coupe based on a BMW 328 chassis. The earliest mass-produced cars that used Kammback principles were the 1949-1951 Nash Airflyte in the U.S. and the 1952-1955 Borgward Hansa 2400 in Europe.

There is controversy about the proportions of a true Kamm tail. According to the classic definition the tail should be cut off where it has tapered to approximately 50% of the car’s maximum cross section, which Kamm found represented a good compromise - by that point the turbulence typical of flat-back vehicles had been mostly eliminated at typical speeds. Thus a minivan is not a Kammback, and neither are numerous cars that have truncated tails. Several automakers including American Motors (AMC) and General Motors (GM) have publicized certain models with truncated tails as “Kammbacks” even though they do not meet the classic "50% cross-section" definition, i.e. the AMC AMX-GT and Pontiac Firebird-based "Type K" concept cars.

Automakers’ use of the term “Kammback” has diminished as Kamm's principles have become more generally assimilated into modern car design.