(GT1/GT2 vehicle outline)
The basis for the GT1/GT2 class distinction lies in areas such as engine displacement and the extent of modifications carried out on the vehicles. In terms of displacement, those vehicles with engines rated higher than 5,500cc are entered into the GT1 class. Moreover, manufacturers have the choice of entering cars rated in the 5,001-5,500cc range in either GT1 or GT2.

As for the base vehicles, these must be commercially-available cars, of which at least 300 have been produced within a consecutive 12-month period; and further, for those models where over 1,000 units have been manufactured within a consecutive 12-month period, exchanging engines is approved for units produced by the same manufacturer in an amount of over 5,000 units within a consecutive 12-month period. In accordance with this, the Nissan GT-R is also supplied with the 5,552cc VK56DE engine.

In terms of maximum output, the GT1 class stands at 600hp, while in GT2, where the range of modifications is more limited, it is set at between 450 and 500hp. Looking purely at engine performance, GT500 machines in the SUPER GT series excel, but major changes to the size of the passenger space or shape of the car from the mass-produced models is not allowed. In short, maneuverability will be influenced according to the latent ability of the base car.