What Jake says is absolutely right on. The power under the curve is quite noticeable, the peak increases not so much. "Massive power increase "? No, but definitely noticeable, not like the giant leap from 1to 2. What I Really like about my Stage 2 is the down pipe and turbo muffler delete, the third and fourth gear pull and just the feeling that the power is better. Stock, at 170hp is adequate,,but just.,coming from a 2014 4.0 A8 with 560hp.....the Alltrack is much more practical and suits my lifestyle, the A8 a friggin beast 0-60 in 3.8seconds but I saw expensive maintenance down the road and traded it with 43k on it.