Instructions
Enable the "Nitro" cheat on the PC version of Grand Theft Auto IV. Start the game by clicking "Start," "All Programs" and selecting "Grand Theft Auto IV" from the list of installed programs.
Watch the introductory story and allow the game to load into your current mission.
Type the code "COXEFGU" at any point during game play. Look for the alert titled "CHEAT ACTIVATED" at the top of the screen after the code has been input. Your vehicle now has turbo capabilities.