Dear AquaTune: I'm the worst skeptic in the world and a good tester because I leave no stone unturned! Now I know that you're not just perpetrating a fraud. This system definitely works! I got an astounding 18.5 mpg on the run where I was typically getting 11 mpg previously. Let me tell you, my '85 Bronco, 5.8L, 4 valve HO Ford engine with 127K miles on it is running better than ever before. It is smoother, quieter and my sticky valve is stuck no more. Even the rattle in my CAT converter is gone. Can't explain this but, it sure is running smooth and cooler and no more predetonation. I am stoked. I can bury the needle without even flooring the engine. I have power to spare on the top end. It feels like I have a ram air system installed. You keep your foot steady and it just keeps accelerating. My Bronco feels like a mustang on the top end. Even at 85mph, when you step on it, it puts you back in your seat. The installation was fast and though I made a lot of mistakes, Tech support was wonderful. I never felt left alone. Thank you AquaTune for a wonderful product!