sometimes from what I've read. Apparently synthetic molecules are more uniform and are smaller so are able to go where dino oil can't, plus sometimes detergents in the syn. remove the dino oil build up that formed around the seal, and this causes a leak. However, the leaks can also seal themselves after a bit as the synthetic can make the seal more pliable once it has been "cleaned" and then it seals again. If you're having a leak problem you could give it a couple months and see if it resolves itself. Otherwise, you could always try switching back to regular oil and see if it clears up your problem after a few hundred miles.
