I have used year around Motul 5/40 synthetic oil with very good results, in most of my cars!! but You can use any American oil Texaco 10/40 or Mobil 1etc…. most oils today have the same quality specification iso , so use the brand that you prefer , Joey is right on one thing ,use from 10/40 or 15/50 if possible all year around is the best protection you can get .
Saludos