I see that a pure 1 is semi synthetic and so is the mobil1. Other than flow and someone says one or the other filters better--------------What does the extra 5 bucks buy me with the mobil1 filter. Been using pure1 with no probs forever. Why would I change. And I don't think the Mobil1 has that much filter capacity diff. Just wondering what you guys thought. I will change if it is the best.