This feature, however, must be turned on after every pit stop because it will reset to normal speed. The speed of the time in the race can be increased up to a factor of 3, allowing endurance races to be completed in less time than would take in A-Spec mode. The new B-Spec mode puts players in the place of a racing crew chief: telling the driver how aggressively to drive, when to pass, and mandating pit stops (by monitoring tire wear, fuel level, and oil dirtying). A-Spec points cannot be redeemed for anything in the game, and they can be thought of as a precursor to PlayStation trophies. There are also the 34 Driving Missions which can yield 250 points each. Points can only be won once, so to win further points from a previously-won event, it must be re-won using a car with less of an advantage over the AI. Players can make their cars less effective by adding ballast weight or running the engine until it needs an oil change. Generally, a win using a car with less of an advantage over the AI opponents is worth more points. Each race event can yield up to a maximum of 200 A-Spec Points.

Players now accumulate points by winning races in the normal first-person driving perspective, called A-Spec mode. A PSP enhanced port entitled Gran Turismo Mobile was originally planned, but was later dropped and replaced by a new project, Gran Turismo (PSP), which was released October 1, 2009.

A limited edition, Gran Turismo 4 Online, was released in Japan in the summer of 2006. The Chinese, Japanese and Korean versions of the game were bundled with a 212-page driving guide and lessons on the physics of racing. The game also features 51 tracks, many of which are new or modified versions of previous original courses, with some notable real-world additions, such as the Suzuka Circuit, or Le Mans Circuit de la Sarthe. GT4 features over 700 cars from 80 manufacturers, from as early as the 1886 Daimler Motor Carriage and as far into the future as concepts for 2022. GT4 was delayed for over a year by Polyphony Digital, and had its online mode removed (later added as a stand-alone online test version) during development. Gran Turismo 4 is one of only four titles for the PlayStation 2 that is capable of 1080i output, one of them being Tourist Trophy which was also created by Polyphony Digital. It was released on Decemin Japan and Hong Kong, Februin North America, and Main Europe, and has since been re-issued under Sony's 'Greatest Hits' line.

Gran Turismo 4 (often abbrieviated as GT4) is a racing video game for Sony PlayStation 2 which is published by Polyphony Digital.

Gt4 garage editor