Forza Motorsport 4 is the fourth installment in the Xbox exclusive race simulation series. It holds many car and race licenses and allows players to race in a realistic setting. The main career mode is now called World Tour Mode and takes players to different races on locations all over the world. Opponents now have adaptable AI based on the player's performance. A lower difficulty no longer leads to less power for the opponents' cars. Instead, they are given less confidence going into corners. This means that players are encouraged to outbrake them instead rather than overtakes on a straight section. The game features new car upgrades called affinity levels, which can be applied to all cars of a certain manufacturer. There are 50 levels for each manufacturer and they apply regardless of the specific car. Three new real races have been added: Hockenheimring, Indianapolis Motor Speedway, and Infineon Raceway, along with a fictional one: Bernese Alps.
Players can import their profile from Forza Motorsport 3 and transfer in-game credits and gifted cars. The game supports both classic controller mechanism and gestures-based control through the Kinect peripheral. Players can use the Kinect to change perspective based on head tracking, while steering is done by moving hands in the air. Both control mechanisms can be combined for a more immersive experience.
Players can create clubs and share cars in garages among club members. A feature called Autovista allows players to walk around and explore a vehicle using Kinect. However, this feature is only available for a limited number of cars. The game also supports online multiplayer, with up to 16 players able to play together both offline and online.