This isn't a dead horse topic as I can't find a detailed discussion about it on this forum. My brother bought a gx460 1urfe (very very similar to the 3urfe 5.7). He lives in a very hot climate all year round in the usa. If I were him I'd be running 5w30 despite the reccomended 0w20. From My oil research there doesn't seem to be a huge difference between those two different grades of oil. But from my research toyota/lexus reccomends 0w20 only in the usa, and other countries they are told to run 5w30- 15w40. I want total confidence to tell him to run 5w30 or 0w30 over 0w20. Anyone have any more info on this topic? Any advice