A prime example of Forza's physics being way off the mark is how easy it is to get a fwd car to oversteer. Irl, fwd cars understeer like a bitch, infact irl most road cars understeer fwd, rwd, 4wd, they all oversteer if you try to corner too fast. In Forza, the cars do not understeer like they should, the braking is largly to do with the tyres. As I said, Forza is good in that area, the suspension isn't that great, the collision phyics while crap in GT4, are stupider in Forza, in GT4 cars bounce off things, in Forza they stick to them like they're coated in tar. In GT4 if you use the simulation tyres on road cars your lap times generally will not be that far off the mark, speaking or realistic lap times, you do realise that Forzas are much further off the mark than GT4's don't you. However I've said this many times in the past, close lap times in a game are not a testiment to the games accuracy physics wise, they can be doctored. But honestly, if you want a more indepth discussion of physics and how it all works, search for an existing GT4 v Forza thread and you'll see some pretty indepth stuff in thoes. Forza doesn't touch GT4 when it comes to realism.