Although the game series Gran Turismo has set a standard for realistic racing simulators, they have a few fictional vehicles in their games which are based on real physics and material capabilities. Some of them are just fictional modifications of real vehicles, while a few are completely original.
Red Bull X
The Red Bull X car is based on "what could be" in a racing series without any regulations at all. This super-high performance vehicle first appeared as a 2010 model in Gran Turismo 5, and this was followed by the 2011 model as downloadable content. Gran Turismo 6 introduced the X2014; noteworthy changes to this model include a full-width rear wing mounted lower, deeper front wing, and reduced power to make it easier to drive. There was also a smaller Junior model of the X2014.
Generic Open Wheel Cars
Some of the Gran Turismo series has had open wheel cars which aren't based on any real series (like Indy or Formula 1). These cars either go by the name "Formula Gran Turismo", or have a code name like "F090/S".
- Chevrolet Camaro LM Race Car
- Honda S2000 LM Race Car
- Jaguar XJ220 LM Race Car
- Mazda RX-7 LM Race Car
- Mitsubishi CZ-3 Tarmac Rally Car
- Toyota Altezza LM Race Car
- Toyota RSC Rally Raid Car
Fantasy Racing Versions
Every installment of Gran Turismo has had real models modified to compete in a racing series they haven't actually competed in. Some wer based on real race cars as well, but weren't painted like the actual competing vehicles.
Vision Gran Turismo
Starting in Gran Turismo 6, the GT team set up a fantasy vehicle development challenge for real-world manufacturers, allowing creative teams to let their imaginations run free, developing an ideal model.