Initial D Arcade Stage 4 is the sequel to Initial D Arcade Stage Ver.3. This version has been heavily updated compared to its predecessors. The game underwent location testing from October 21, 2006 to October 30, 2006 in game centers in Tokyo, Osaka, and Aomori, Japan, and was released on February 21, 2007. The international version was released in July 2007 which is named Initial D 4.
Unlike the older games in this series, which were revisions of the original title, Initial D Arcade Stage 4 has a completely new physics engine written by Sega Rosso for the Sega Lindbergh arcade system. This new system allows cars to actually slide, or drift, across the track when turning corners; this is a feature not present in the older games. Initial D Arcade Stage 4 features animated cel-shaded characters interacting with each other, while the cars and environment use updated, high-definition graphics. The cabinet has a 32-inch 16:9 LCD screen supporting WXGA resolution (1366 x 768). The gear shift has been relocated to a lower more realistic location. The Japanese version of the game supports connection to Sega's All.Net online play network, allowing players from different arcades to play against each other.
The player cards for saving gameplay data have been changed to IC cards like other Lindbergh games such as Virtua Fighter 5, and Power Smash 3. The player can store data such as their vehicles, modifications to vehicles, avatar customizations and time attack times. Additionally, unlike the past three versions of the game, in which the player is limited to one car per card, the player can now store data for up to three different cars. Additionally, the IC Card can be used for 150 plays, as opposed to cards for past versions which can only be used for 50 plays. Players will not be able to transfer data from versions 1 through 3 due to the changes in both the player card and the card slot. The modification system has been updated as well, as car upgrades are no longer automatic, allowing players to choose which parts to upgrade and how they spend their reward points.
Source: Wikipedia, "Initial D Arcade Stage 4", available under the CC-BY-SA License.