Soon as they have a killer blend they change it. Started with M1 R4T, next M1 10w30 HM, the 0W20 EP and recently a fav around here M1 0W40 FS. Bean counters in for the Loss! I am done.That's because you didn't buy the Annie Oakley Mobil-1 EP Triple Action 5w/10w30.
In your climate I'd say 10w summer and 5w winter.