What was the PSP game Gran Turismo originally titled during development?

The PSP game Gran Turismo was originally titled Gran Turismo 4 Mobile during development.

Polyphony Digital announced the project alongside the original PSP at Sony’s E3 2004 press conference. It was intended to bring a full Gran Turismo experience to Sony’s handheld, but development continued for years as the studio focused on other demanding projects, including Gran Turismo 4 and Gran Turismo 5.

The game was known by several working or descriptive names during its long development, including Gran Turismo Mobile, Gran Turismo 5 Portable, Gran Turismo Portable and Gran Turismo 4.5. That history causes a common quiz trap: “Gran Turismo Portable” sounds like the most obvious original title, but the specific early development name documented for the project was Gran Turismo 4 Mobile.

When the game finally reappeared in playable form at E3 2009, it had been simplified to the straightforward title Gran Turismo. It launched for PSP on October 1, 2009, including as a launch title for the PSP Go.