Update: Microsoft has revealed much needed information about the second disc that will come encased with Forza Motorsport 3 saying that players will be able to play the whole career on disc one, and that the second disc is just extra content.

“The game comes on two discs, but you can play through the whole career on disc 1. Disc 2 is just additional content, ie extra cars and tracks,” a spokeperson told GamerCenterOnline. Or, in other words, Forza Motorsport 3 has alot of “extra content”.

Original: Because not all the cars and tracks could fit onto one disc, Turn 10 had to split Forza Motorsport 3 onto two discs. The first disc is most of the game, which features most of the tracks and about 300 cars, and the second you’ll need to install the onto the hard dive or memory card to get the remaining 104 cars and 29 tracks, reports IGN.

When you insert the first disc, the game will ask if you want to install the second disc, which takes up 1.9 GB of space. However, if you don’t have that much space on your hard dive, you can choose pieces of disc two to install – in which it’s broken up into four packs, much like downloadable content (IGN has a list).

After that, the game reads it and adds in the content seamlessly to the game. If you don’t have them stored onto your hard dive or memory card, you won’t see the content offline or online. We’ve contacted Microsoft to learn more about these packs, and if they’ll be fully available right at the games launch.