I saw an online demo of this oil additive and couldn't believe my eyes. The thing really works! I add it to my oil when I change my oil. About 4 ounces each time. I don't buy synthetics now, just regular oil and this additive. I've been doing this for several years now. I've only done about 40,000 miles in three cars so I can't say if this will extend the life of my engines, but I think my engines will run longer based on the videos I've watched.