i experimented with mobil1 0w-40 in my engine during the last oil change. it's worked out okay so far, but the ticking seemed to return sooner than when i use the 0w-30. i was hoping that the "heavier" weight would increase oil pressure, but i could not appreciate any increase in oil pressure over the 0w-30. it fended off the tick longer than the 5w-30 typically does though. ymmv, hth