5w 30 is not recommended for hotter climates. i doubt PA qualifies as a hotter climate.
10w30 is recommended for most climates EXCEPT extremely hot or cold. i would run 10w30 since that is the factory spec. but seeing as how the engine has made it this far on the 5w i doubt it makes a difference.
but more important than the type of oil is the fact that you change it. i don't think 180k is a significant mileage for selecting a different oil. but oil is one of those things where everyone has an opinion and everyone has a favorite. and we all have a reason it.