Just found this thread. This is not snake oil folks. I had purchased a Boston Whaler with a bad cylinder / low compression. (Checked by dealer). I used this stuff heavy, let it soak overnight, fired it up to enough smoke to alert homeland security. Took it to a second dealer close to home and asked him to check it out thoroughly. Called me in an hour and said pick it up. I got there thinking I was gonna get the blown motor talk. Nope, compression 115 in ALL cylinders. Take her home and run it. Which I have for two years. Carbon build up can cause rings not to seat properly, at least in boat outboards. Apparently I loosened carbon deposits. I run Chevron with Techron too, as I'm a believer.
