The Porsche 911 Carrera (993) is the fourth generation model of the Porsche 911 series, replacing the previous generation 964 in 1993. The 911 (993) evolved with improved construction of the body to an all-alloy subframe, and was the first generation of the 911 model series to have a 6-speed manual transmission. In addition, it was the last generation of the 911 series to feature air-cooled engines. The 993 series was succeeded by the 996 in 1998.