http://wccftech.com/gran-turismo-sport-demo/

Sony has announced that a free 4-day Gran Turismo Sport demo will be made available next week on October 9 ahead of the game’s release later this month.

The demo will be made available on October 9th at 6:00pm PT and will officially end on October 12th at 8:00am PT. PS Plus members will be able to pre-load the demo starting from October 7th at 8:00am PT, with access to the game on October 9th, at 12:00am PT.