I'm not a big review writer but I have to say that my engine appears to run smoother on long rides. As for the smoke in the tailpipe upon start up. The Detox did not work. My Audi A6 still smokes for a several seconds on start up. I don't think there is no real "liquid" solution that will replace a mechanical repair. Maybe the tune up solution helped improved the overall performance of my engine but it didn't solve any of my start up problems. The engine cleaner definitely helped get some of the old oil build up out. So I don't believe my purchase was a total lost.