Gran Turismo 4 is a 2004 racing video game for the PlayStation 2, the fourth installment in the main Gran Turismo series and the sixth for the overall series. It was developed by Polyphony Digital and published by Sony Computer Entertainment and was released on December 28, 2004, in Japan and Hong Kong, February 22, 2005, in North America, and March 9, 2005, in Europe, and has since been re-issued under Sony's 'Greatest Hits' line.
Originally planned for a 2003 release, Gran Turismo 4 was delayed for over a year and a half by Polyphony Digital, and had its online mode removed. The game features over 721 cars from 80 manufacturers, from as early as the 1886 Daimler Motor Carriage, and as far into the future as concepts for 2022. The game also features 51 tracks, many of which are new or modified versions of old Gran Turismo tracks, with some notable real-world additions.