Kammback

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A Kammback, or Kamm tail, is a car body style that derives from the research of the German aerodynamicist Wunibald Kamm in the 1930s.

Contents 1 Aerodynamics 2 Kammback examples 2.1 High-performance cars 2.2 Mass-production cars 2.3 Hybrid mass-production cars 3 References 4 External links

[edit] Aerodynamics

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Kamm showed that a better drag-reducing tail-end design for a car is a tapering teardrop shape that cuts off abruptly.

Prior to his thesis, the teardrop tapering smoothly to a point was considered optimal. Kamm showed that an abbreviated teardrop actually worked better; the air still flows as if the entire teardrop were still there, but without the surface drag of the long point.

There is controversy as to the proportions that constitute 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, because Kamm showed that this is the point at which the aerodynamic drag begins to increase. Thus a minivan is not a Kammback, and neither are numerous cars that have truncated tails.

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. ^[1]

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

[edit] Kammback examples

[edit] High-performance cars

The Kamm tail was used on many high-performance and competition cars, such as:

• 1940 BMW 328 "Mille Miglia" Kamm coupé ^[2][3]
• 1962–1964 Ferrari 250 GTO
• 1963-1974 Bizzarrini Iso Grifo^[4]
• 1965-1968 Ford GT40^[5]
• 1965-1970 Aston Martin DB6
• 1968-1973 Ferrari 365 GTB/4 (“Daytona”)
• 1968-1976 Ferrari Dino^[6]
• 1970-1975 Citroen SM
• 1970-1977 Alfa Romeo Montreal
• 1972-1982 Maserati Khamsin

[edit] Mass-production cars

Kamm (and Kamm-like) tails can be seen on numerous mass-production cars, such as:

• 1970-1986 Citroën GS
• 1970-1993 Alfa Romeo Spider
• 1974-1991 Citroen CX
• 1984-1991 Honda CRX
• 1985-1996 Autobianchi/Lancia Y10
• 1991-2005 Audi A2
• 2001-2008 Volvo S60

AMC and GM have publicized certain models with truncated tails as “Kammbacks” even though it is obvious to the eye that they do not meet the classic "50% cross-section" definition, i.e. the AMC AMX-GT and Pontiac Firebird-based "Type K" concept cars, ^[7] a Chevrolet Vega station wagon, ^[8] and a version of the AMC Eagle. ^[9]

[edit] Hybrid mass-production cars

As the Kamm tail’s low drag helps improve fuel consumption, it features on subcompact hybrid cars designed for maximum economy, for example:

• 1996-2006 Honda Insight
• 1997-2008 Toyota Prius

[edit] References

[edit] External links

• Article on the origins of Kammback design
• The Pininfarina 1800 - an explicitly Kamm-influenced design which informed the Citroën CX and Rover SD1