Originally Posted by GregW / Oregon
It's basically like the one in the E46 M3. To quote Car Magazine from their M-Division tour article,
"The M-differential lives on in the E92. It's based on the same principals as before, but the components are new. That means the diff is mild under turn-in to avoid understeer, but locks up progressively with up to 100% lock-up possible. As before, it's less aggressive under braking than acceleration, so it won't give a tricky handbrake-effect as on the more track-biased LSDs."
The diffs change from M3 to M5 - 3.91 in M5 and this is what I am guessing will be in the new M3. I was just looking for some confirmation. The 3.91 is what I installed in my 04 M3 and the difference from the standard diff is night and day. 4th gear feels like mid peak 3rd and it lists the rear to the right when I get on the throttle.