Center Diff
 

Looking for more info on the center diff. Since my real truck has a transfer case I always think about 4x4 = locked in the center. So I am a bit confused as to the locking center diff in the game.

With the center unlocked does it act like an open diff, or a "Full Time 4x4" system (which is a limited slip system I guess)?

Or is this a feature that has little impact on the game? I noticed in 2 wheel drive I have WAY more traction than I would expect from a 2 wheel drive truck with an open diff, which makes me think all the diffs act as limited slip diffs until you lock them.

Where would I *not* want to have the center locked up? And on that note, where would I not want to be in 4 wheel drive?