This site has changed my thinking a lot since I found it. I now use Mobil 1 rather than Royal Purple. I use a premium Oversize Pureone oil filter rather than OEM. I check all manufactures before purchase of air filters. It has to be as good or better than the OEM it replaces. NAPA GOLD has been the winner so far. My autos are being treated with auto-rx and techron. How has this site changed your thinking?