I have used auto rx on several cars. It does work. You have to remove your valve cover before you use it and after 6000 miles of driving. You will never know what it does unless you do this. I replace my filter 3 times not 2. It may stop seals from leaking, but I always replace seals as needed. They get old and brittle. What do you expect. Cars need maintenance. Auto rx will clean and free piston rings. This takes time. 6000 miles and some cars will need a second treatment. Some people are not patient. By the way I am not a paid blogger. Just a guy who keeps my family and friends cars running.