Hmm, you probably won't have issues - your car is *only* five years old.

The other school of thought is to use a semi-syn if you're concerned about old seals leaking (seriously, five years is NOT old).

I think you'll find the five cylinder engine to really like syn or a semi-syn. It will rev smoother, the turbo will be heaps happier, your gas mileage will improve, and best of all, your engine will be a lot cleaner than on dino. I have an 850 T-5 and I am using a Valvoline semi-syn so that's been my experience. My experience with dino oil in a normally aspirated 5 cylinder is the same - not so good. The engine runs a lot less lethargically and is cleaner with a semi-syn or syn. The cleanliness helps the flame trap to clog up less frequently, which is a good thing, since the last time it did, I blew out the rear engine seal and the engine caught fire when the oil hit the exhaust ;-).

Good luck.
Lucast