Wankel engine [Wankel Engine in Deutsches Museum, Munich, Germany]The first working prototype of the Wankel rotary engine ran for the first time on February 01, 1957 The Wankel rotary engine is a type of internal combustion engine, invented by German engineer Felix Wankel, which uses a rotor instead of reciprocating pistons. This design delivers smooth high-rpm power from a compact, lightweight engine; however, Wankel engines have been criticized for poor fuel efficiency and exhaust emissions. Since its introduction in the NSU Motorenwerke AG (NSU) and Mazda cars of the 1960s, the engine has been commonly referred to as the...