I'm suprised to see so many people running synthetic oil. How many of you guys started using synthetic oil at real high mileages (90K+ miles)? I always hear stories of people leaking oil big time after switching to synthetic in high mileage engines.

Also, I thought the owners manual said not to use 5W-30 oil for "sustained high speed driving". What does that mean exactly? I don't plan on running the Indy 500 in the SVX anytime soon