<Tr> <Th> Layout </Th> <Td> Rear - engine, rear - wheel drive / four - wheel drive </Td> </Tr> <Tr> <Th> Related </Th> <Td> Porsche 911 GT1 Porsche 911 GT2 Porsche 911 GT3 Porsche 912 Porsche 930 Porsche 934 Porsche 935 Porsche 959 Porsche Boxster Porsche Carrera GT Ruf RGT </Td> </Tr> <P> The Porsche 911 (pronounced Nine Eleven or German: Neunelfer) is a two - door, 2 + 2 high performance classic German sports cars made since 1963 by Porsche AG of Stuttgart, Germany . It has a rear - mounted six cylinder boxer engine and all round independent suspension . It has undergone continuous development, though the basic concept has remained little changed . The engines were air - cooled until the introduction of the Type 996 in 1998, with Porsche's "993" series, produced in model years 1994--1998, being the last of the air - cooled Porsches . </P> <P> The 911 has been modified by private teams and by the factory itself for racing, rallying, and other forms of automotive competition . It is among the most successful competition cars . In the mid-1970s, naturally aspirated 911 Carrera RSRs won major world championship sports car races, such as Targa Florio and 24 Hours of Daytona, even against prototypes . The 911 - derived 935 turbo also won the 24 Hours of Le Mans in 1979 and Porsche won World Championship for Makes titles in 1976, 1977, 1978 and 1979 with 911 - derived models . </P>

When did porsche go to water cooled engines