I have to say it was nothing like I have seen on youtube. I did the spray version. Sprayed it on the throttle body plates (1/2 can each) and let the car sit for 10 min. There was some smoke for about 10 min after but not as bad as I had expected. Idle is a lot better and the car runs a lot quieter. Smoke that came out was mostly black and gray, not white like I have seen in the videos but my piston tops were pretty bad.