I got the minimum of four oil changes of at least 4000 miles each before you could START to see a difference between using it and not using it. The guy was a Valvoline tech support rep that told me this on the telephone. It adds up to a minimum of 16,000 miles of use before you MIGHT BE ABLE TO SEE A DIFFERENCE. He also let me know Valvoline doesn't replace worn out parts and worn valve or oil seals. It won't cause an engine that needs overhauled to stop burning oil. Valvoline Restore and Protect is their top gasoline engine oil, and the cleaning thing is nothing but a side effect of using it. It has a slow cleaning side effect but doesn't do engine overhauls and replace worn out seals all by itself! LOL! Anyhow, I got the 16,000-mile use number directly from a Valvoline Tech guy employee, along with the rest this stuff I just typed on a rather long phone discussion I had with him. I am thinking if you bought a brand-new car, especially one that is prone to getting ring deposits, maybe you could avoid the problems to begin with? And yes, the cleanup could take 100,000 miles or more, depending on how dirty the insides are, I guess. That still doesn't mean it will reduce oil consumption on that engine; it depends on the cause of the oil consumption to begin with.