I treated a tank of V-Power in my wife's 2006 Pilot with Amsoil Pi (new formula) a couple of months ago. It seemed to work well, though it is difficult to tell conclusively. The engine only had ~22K miles at the time, so I was not expecting a huge difference. I could detect a pungent exhaust odor each time the engine was started, which leads me to believe that the Pi was potent enough to remove carbon deposits. That is not a very scientific approach though. I guess a better test would be to use Pi in an engine that is somewhat older and has used cheap fuel for an extended period of time. Amsoil usually sells only top notch products, so I am sure that extensive testing was performed. I read somewhere that Pi is made by Amsoil using chemistry from Lubrizol. It would be good to see some head to head testing of Pi, Techron and Redline, though I doubt we will ever see that happen.