For what it's worth, went to my Nissan Dealer today to get the oil changed. I discussed the merits of synthetic oil (Mob 1) with a mechanic and a Serv Advisor.
Both said the X's engine was designed for regular oil and that synthetic is not the best way to go. They also didn't believe the Mob 1 filter was the way to go, the Nissan filter was better.
They didn't say that Mobil 1 products weren't good, just not needed.
Just passing on what I heard.