The best in this range Ive used. IMO, Better than PU or M1, or QSUD.
Valvoline Synpower 0w20. Better formula than their 5w30. Must be magic sauce.
I might try Magnetec - I haven't seen a 5w20 or 0w20.
and Yes you can run 5w20 in normal Climes; If not, engine is Junk.