The Porsche / Volkswagen Schwimmwagen used the engine and mechanicals of the VW Type 86 four-wheel drive prototype of the
Kübelwagen, also used for the Type 87 four-wheel drive 'Kübel/KDF' Command Car (
Kommandeurswagen), which in turn were based on those of the civilian
KDF-Wagen.
Erwin Komenda,
Ferdinand Porsche's first car-body designer, was forced to develop an all-new
unitized bodytub structure, since the flat
floorpan chassis of the existing VW vehicles was unsuited to smooth movement through water. Komenda patented his ideas for the swimming car at the
German Patent office. The initial Schwimmwagen, Type 128 prototype, was based on the full-length
Kübelwagen wheelbase of . Pre-production units of the 128, fitted with custom welded bodytubs, demonstrated that this construction was too weak for off-road use. It had insufficient torsional rigidity, and easily suffered hull-ruptures at the front cross-member, as well as in the wheel-wells. This was unacceptable for an amphibious vehicle. The large-scale production models (Type 166) had a reduced wheelbase of which resolved these issues. Schwimmwagens were produced by the Volkswagen factory at Fallersleben /
Stadt des KdF-Wagens and Porsche's facilities in
Stuttgart; with the bodies (or rather hulls) produced by
Ambi Budd in Berlin. 15,584 Type 166 Schwimmwagen were produced from 1941 through 1944; 14,276 at Fallersleben and 1,308 by Porsche; the VW 166 is the most-produced amphibious car in history. Only 189 are known by the Schwimmwagen Registry to remain today, and only 13 have survived without restoration work. ==Technology==