I have an odd coincidence, at least, I hope it is merely a coincidence. My current is a '94 945T with 126k miles. Had an oil change at 125k, thought I would upgrade to Mobil 1. Less than 500 miles later the head gasket blows while going down the interstate. The same thing happened with my prior vehicle ('88); change to syntetic oil followed by blown head gasket. Can't handle improved compression? Stick with the basic 10/30? Something in the way I drive? I'm a conservative highway driver and take good care of the basics. Anyway to predict/monitor/prevent these types of surprises? All the old beater cars I had growing up never blew a gasket; luxury european import made for the autobahn and boom times 2.