RP has a good product but there's nothing magic about theirs compared to other synthetics. The only complaint i've personally heard was from a truck company that tried it for a while. Did a "heavy haul" out of New York and was short 8 qt. at the end of the day - no leaks or usage problems before. Wouldn't think twice about using a named brand synthetic in my car or boat if I had a 4 cycle engine.