Which game will sell more first week WW? Forza 3 or Grand Turismo 5?

[FootballFan]

Considering even a portable gran turismo has more cars than Forza im presuming Gran Turismo 5 will have even more. Graphics look identical to me. Gran Turismo on what we have seen will most likely be the better game and obviously the better name.

Forza M 500,000
Gran T 1,000,000