It doesnt have to say that, but if you want to go the factory interval you need decent oil. If you were going 5k, maybe you could use another high quality full synthetic, but if its gonna be 10-12k youll need the 502/505. Mobil 0/40 meets 502/505, BMW LL-01, Porsche A40, and Mercedes 229.3, not sure about 229.5
The problem with those motors is the fuel dilution, so you need something to be able to stand up to that.