I sell it at NAPA, but I always tell people that I'm not sure it works if they ask.
The part I think is funny is that the same people who say they don't like to mix brands of oil or change wieghts in a motor WILL ADD LUCAS TO THEIR OIL! ???
Strikes me as odd. Plus it's "100% Petroleum" as per the label. Since I use synthetic, I don't feel the need to downgrade.