[flintworks]

2 out of the 3 dealerships I've worked at used Mobil 1 0w-40. We're talking about thousands of oil changes a year just from one dealership. If there was a problem with that oil Porsche would remove it from the approved oil list and we would have seen more internal engine problems. The third dealership used Valvoline 0w-40 simply because it was cheaper than Mobil 1 and I believe Porsche approved it for use this year. In my opinion it's more important to keep the oil clean than debate which synthetic has the greatest protection.