Although Porsche introduced the 964 series with a 3.6 liter engine in 1989, the Turbo version, introduced in 1990, inherited an improved version of the 3.3 liter engine from the second generation 930 Turbo. The 3.3 engine produced 320 hp at 5,750 rpm, making the Turbo the world's fastest-accelerating production car at that time. An even more performance oriented variant, the Turbo S (Lightweight), produced 375 hp. While most were produced in coupe form, a very limited number were built as cabriolets through Porsche's Special Wishes program. The Turbo 3.3 ended production in 1992 (with some registered in 1993), and was replaced by the 964 Turbo 3.6 in 1993.