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.
If thats the risk you wanna take go for it. Just because you can't hear it pinging doesnt mean its not. I would definitely drive it as easy as possible to reduce engine load.