[RWebb]

Can anybody explain the different systems out there?

Subaru is pretty proud of their 50-50 split all the time -- or whatever they do. They say it is better than the others.

Then there is the VW 4XMotion permanent four-wheel-drive on the Tuaregg...

MB has something they think is special...

None of these are locking diffs (tho Honda Pilots can 'electronically' lock the diff. apparently).

I am thinking in terms of snow; mud & gravel roads, not rock crawling or anything like that...