Gran Turismo is described as 'The first installment of the Gran Turismo series of games. Released on December 22, 1997, it featured quality gameplay and graphics tuned toward a realistic driving experience with 180 different vehicles and 11 race courses. It was developed by Polyphony Digital Inc' and is a Racing Game in the games category. There are more than 25 games similar to Gran Turismo for a variety of platforms, including Windows, Android, Playstation, Xbox and Steam apps. The best Gran Turismo alternative is Need for Speed. It's not free, so if you're looking for a free alternative, you could try Stunt Rally or Nitronic Rush. Other Gran Turismo like games are BeamNG.drive, Assetto Corsa, Forza Horizon and TrackMania.
Need for Speed is for the best part, a story based illegal street racing game that does not have realistic car physics or circuit based "career" type racing. Gran Turismo is much closer to real world physics and is purely focused on real world racing.