När Sony visade upp PSP på E3 fick vi även se Gran Turismo på maskinen. Vad som nu är bekräftat är det faktum att GT4 till PSP kommer att vara en direkt portning av originalet till PS2. Spelets producent, Kazunori Yamauchi, vill ha lika mycket innehåll i den bärbara versionen. Vad passar då bättre än att konvertera spelet direkt från PS2, då PSP har liknande kapacitet som maskinen.
"The PSP is a portable game machine, and people may think it's oriented towards playing simple games, but it really has the same hardware performance as the PS2. Since we're already developing the GT4's system on the PS2 hardware, we're planning to port that directly to the PSP.
There's basically two ways of making games for the PSP. One way is to develop an original new game, which in general will be limited in its content since the price of PSP games aren't going to be too high, meaning the game's development budget will also be limited. We're going to be taking the second method, which is to take a system from a major title, and effectively sliding it onto the PSP hardware,"