Synthetic vs Petroleum oils
I just purchased a 1995 M3 to make into a track car. It.s in the hands of a trusted mechanic who drives a Ferarri, Benz and several BMWs. We got into a discussion about engine oil, and his personal experience on changing from petroleum based oil to synthetic. On his 90s vintage cars he often developed leaks in valve cover and other gasket sealed devices shortly after switching to synthetic. Has anyone had similar problems? I'm about to change the oil in my 95 M3 for the first time, I'm not sure if the past owner used petroleum or synthetic and I'm about to use synthetic.