As mentioned, I and others have been guinea pigs and tried 5w's.
The manual says it *CAN* be used. The reccomended 0w20 is for epa #'s.
That said- my brand new XV has Amsoil oe 0w20, and will likely run idemitsu for most of my oil.changes for the entire life of the car. But if I anticipate any towing or heavy duty use, I'll consider a good 0w30.
I have had a dealer put 0w30 in my last car. I couldnt tell any difference.
I'm not at all suggesting that w20 is bad or anything like that. But this is an oil discussion and fb's and oil are something I have spent a lot of time (almost 2 years) experimenting with and researching.