one more thing, there's always gonna be "QD"s in the world that say "ive always done this and it always worked" and that's sometimes 100% true. I have an uncle like that who i respect as much as any mechanic ive ever met. He's used the same oils all of his life and i've seen every vehicle he's ever owned last insanely long amounts of time. He commutes long distances to work and i've seen a lot of his vehicles surpass the 400k mile range with literally no major maintenance at all. Using the ole trusty Castrol and STP oil treatment mix. It wasnt until recently that i converted him to modern technology and proved that not all oils were created equally. Oil is not a guessing game, you can get scientific lab results done on your oil and mailed to your house. I'm currently collecting samples to compare Amsoil vs Mobil-1 vs Harley Davidson oils in Vtwins. If you REALLY want to know whats going on in your engine.... get an oil analysis, it costs $35. If you use Fram filters.... be prepared for them to tell you that they found a shit ton of dirt and filter particles in your oil. Even if what youre doing is good enough, some will still want to do it better and know that what theyre doing is the best thing they can do for their engine.