I agree with the fuel issue. Unless your motor requires a high octane fuel, run low grade fuel, and avoid E fuel if possible. Keep up with your water sep's.
We are in the process of creating this list. I have one made up but this 911 thing has thrown a wrench in it because I can't find a single document other than the TL sent to us that explains what VW91101 is and what spec (501, 504, 505, 506, 507)covers it!
I would agree that Using a good marine grade synthetic oil is not a bad idea and probably would not incure damage to your engine. But if you have a gut feeling, then continue with your conventional 4-stroke oil. After all it is what they did there testing with.
We did contact the manufacturing plant. Only for the purpose of knowing what oil is put in from the factory. They sent a 15 page service bullitin with test data and analysis. There is a lot of data there but unless you are a rocket scientist it might as well be a foriegn lang. The summary states...
It is a BEF LP engine. I work for Linde forklifts. A good majority of our engines are VW. We recieved notification on factory filled engines with specs meeting VW 911 01
It is a 5w-40
I've been a marine tech for 3 years. Yamaha has thousands of engines out there with 5,6, 7 thousand hours on them. A good majority of them run Yamalube. If money is not a problem then why not run it? It does have a good track record. As far as synthetic, Can't help you on that one. I have never...