I just wanted to say thank you to everyone who has helped me understand oil much better and to comment on Pentosin Pentosynth 5W-40 that I am using in my 1.8T 05 GLI. I think I have found my summer oil. I would recommend this oil to anyone. And, I will be posting my used oil analysis numbers soon to see just how good it is working. My MPG went up too. I used ECStuning.com by the way and everything went well! Does anyone have their own experience with this oil?