I've thought about this over the years but end up just using it whenever it is convenient but like other posters mentioned I don't use it much anymore since I use TopTier most of the time. I will mention that my diesel truck has some Power service "Tank Cleaner + Fuel Stabilizer" in the tank since it's been setting idle for most of the year but I run it down the road to get it throughout the system. Some cleaners say every fuel up so IDK.