Baloney! Your vehicle will run (possibly even better) blending multi oil brands and multi viscosities. I've been doing it for 30 years and I'm first and last owner of my vehicles. But.... keep in-mind, I've never exceeded 7K OCIs. OCIs of my length are how you keep the same vehicle and never even change valve cover gaskets, in 18 or-so years of driving it. I don;t even get sludge at 7K. Nor do I get streaky oil, smelly oil, burnt oil or sooty oil..... all signs of something bad going on with your oil and/or engine. But Pt 2..... I now own a GDI engine. So that non-sooty mention may end someday.....lol
Originally Posted by Puckrobber
My understanding, from reading this forum, was that motor oils that have certain additives, would have those additives cancelled out if you add another additive-filled lubricant to the mix. Am I understanding that wrong? At the most, I couldn't imagine it doing any harm to the engine, but, it wouldn't benefit it, either.