I have used LIQUI MOLY oils for quite some time. I decided to try some of the Diesel Purge additive I had heard so much about. I ordered in some and tried it on a vehicle with over 200,000 miles on it. Almost immediately it began idle much smoother, it ran quieter and the black smoke stopped billowing out. Since that day I have offered Diesel Purge to all of my diesel customers and they love it as much as I do. In fact, I have customers come in just to buy a case of Diesel Purge. The nice thing is that Diesel Purge will work on any make & model diesel engine.