Quote Originally Posted by ironchef
Im at 10.5:1 and boosted (A4 2.0t), and had to use 87 last week. I had no problems that I could see or hear. There was a very minor discernable difference in performance, but thats about it.
I also think it is different when it is a factory turbo set up, and aftermarket... Not sure whether you are running factory setup or not, just saying all cars are going to be different.