Just a quick Oil question

[mr_miles]

Getting ready to do the first oil change in the Yaris, and I'm debating going to synthetic 0-20w. I've only got 23k on the engine on what I assume is 5-30 like the cap says. I've typically owned older vehicles where I automatically went to 20-50w or straight 30, never down to a lower viscosity. i guess my main question is - is this a bad idea? short of listening for any knocks or clatters from going to a lower oil, what else should I look for?