Quote Originally Posted by 20774 View Post
Kent -

That website specifically states Mobil 1 viscosities. I wouldn't have any issue with using oils from the same manufacturer. But is it a universal truth that any oil, any viscosity, dino/synth can be mixed? I would doubt it.
Good question and I'll acknowledge here that I don't know the answer to that question but would rely on the guidance from the chemical companies that produce these products. I only referenced the feedback provided by Mobil on their Mobil 1 product -- you would need to direct questions regarding your specific product and issue to the chemical company that produces that product -- for me that is the one (and only) trusted source.