I am now a believer in Mobil 1, 15-50.
I used dino M/C oil before and I could usually smell blow-by upon hard deceleration. Since using the Mobil 1, I no longer smell it.
To spend a few extra bucks to not have to smell blow-by is worth it to me. Also, my breather system is probably not accumulating gunk as quickly.
YMMV... :2thumbup: