I started a thread where my truck was idling rough. Tried several times to fix it, never could. Tried Redline fuel system cleaner, and now the truck feels like its not even running when its at idle. Also my valve clatter stopped, so I no longer have to run 89 octane if I don't want valve clatter. Maybe someone can benefit from my hours of research into the best fuel system cleaner. Redline is it. One bottle treats 100 gallons, but its fine to use it on a normal sized fuel tank. Redline contains the most of any brand of the actual cleaning agent. Only other one that would seem to compare is RXP. Had a good experience, so I just thought I'd share in case it can help someone else.