Why not just go with M1 5w-30? It will serve you well.
quote:your likely right, but see my other thread regarding 20F flow cold flow observations . I'm looking to see how much I can improve these flow number by switching to 0W. M1 0W30 is 680 cSt at 20F, I think the M1 5W30 is more like 900.
By the way, even in Chicago you don't genuinely need 0WX. 5WX is good down to around -25F. Correct me if Chicago gets down to -30F, and I'll retract that last paragraph.
I see you're in Chicago. Check the Lee on Dundee in Northbrook... that's where I bought mine, and they still had some left last time I was there.