actually, the crawl ratio you would get would be slightly better than a rubicion t-case. in general, the benefits of having a lower crawl ratio allows you to creep along on tough terrain rather than having your tires spin thus causing you to loose traction. this is great to have on the rocks or even when snow wheeling. in the mud, i'm not so sure how much it would help as having your tires spin and clean out your tread is a good thing.