Lollllll so what makes you think that GM designated oil is better than synthetic 10w30 in summer. They have had since 2011 to work on this chain problem that does not appear on most cars.
My rav4H has 0w16 but in Australia allows 10w30 all the way upto 15w40 in summer time. Go figure.
Do Australian bound Rav4's have to meet CAFE standards, because that's the principle driver behind thin lubes like a 0w16. I
can use a 5w20 but I run a 5w30 or even 10w30 because i don't give a rats butt about CAFE; I value wear protection over CAFE.. and I still have the original timing chain at 165k miles and have never seen metal flakes to be concerned about.