You do not want to use 15w-50. use either 0w-40 or 5w-40, they both provide a wide range of protection in all enviroments. 15w-50 is not recommended by audi and there is always a reason behind it. 0w-40 and 5w-40 are the only M1 synthetic that are VAG approved

 

It's my understanding that Mobile 1 is synthetic. Why do you think it is not?

 

synthetic is the way to go. any brand that meets the VW 502 $ 505 standards is fine.
All brands note which manufacturers standards their oil meets.

 

Well.. I just checked mobil1.com. Their little wizard is telling me 0w/40 which seems to be a pretty common recurring recommendation.

 

Thanks for everyone's input - I will use Mobil 1 0-40..
Thanks again -

 

I have worked for 2 oil companies and still have a lotto learn,
if your going to use a 5w 30 must be synthetic, the lighter weight
spools turbos faster and still protects well. I like redline but pricy
so usually go with mobil 1, my 87 turbo is still running strong
at 176000

 

i didn't think M1 made a 5w-30 i figured it was a different mobil product. but still 5w-30 is not vag approved and prolly shouldn't be used.

 

5w-30 can be used if it is a sythetic, not if its dino oil.
synthetics lubricate better run cleaner and protect better.

 

the official owners manual states my 2000 2.7 T came with 5w-40 but
5w-30 may be used, and they only mentioned regular of sythetic blend.
so a full sythetic 5w-30 would be fine

 

Has anyone used Royal purple? I tried it and I felt more smooth shifts and throttle response compared to castrol syn I used before.