This debate has been raging about since synthetic motor oil was introduced years ago. Some (here) have performed the switch with good results. Others have had leaks.

My first SAAB's motor mad it to 300,000 miles, on Castrol GTX, not on synthetic.

I currently use synthetic oil in our two newer cars, mineral oil ("dino juice") in the two older cars. The 2 newer cars have "always" had synthetic. The two older cars have "always" had mineral oil. None of the 4 really uses any significant amount of oil, one of the older cars has about 180,000 miles on it.

My own thought about your question is something that I learned years ago:

1.) If what you are doing is working, keep doing it.

2.) If what you are doing is NOT working, try something else.

-Punxsutawney Phil