Ive seen a few posts recently saying that synthetic oil is better for our S60's with the turbo. Ive been using 5W30.

Should I switch to syn oil and why?

 

You can decide for yourself.

Synthetics can offer the turbo owner extended oil change intervals.
less possibility of sludging
better cold starts
less deposits
possibly better protection against wear

Turbos run hotter and the flash points on the synthetics are higher than dino oil.

 

I would only use Synthetic. I would never ever run traditional oil in a turbo.

 

Synthetic all the way.