Also known as a “Kammback” a Kamm Tail 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.
While the realities of fluid dynamics dictate that a teardrop shape is the ideal aerodynamic form, Kamm found that by cutting off / flattening the streamlined end of the tear at an intermediate point, and bringing that edge down towards the ground, he could gain most of the benefit of the teardrop shape without incurring such a large material, structural, and size problem. The airflow, once given the suggestion of the beginning of a turbulence-eliminating streamlined teardrop tail, tended to flow in an approximation of that manner regardless of the fact that the entire tail wasn’t there. This is called the Kamm effect.
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.
Automakers’ use of the term “Kammback” has diminished as Kamm’s principles have become more generally assimilated into modern car design. Kamm Tail content courtesy of Wikipedia. Corvsport Page References: C4 Overview, 1974 Overview.