It appears you maybe new, but this topic has been beat to death here. SWHEATON on this board is the expert. He's spent a lot of time and his own money for testing ect.
Instead of a quick answer, I would read through the above link and read about the details and tests on oils and additives and the links associated. Its not in most cases just throwing some good oil with a additive, not a good choice. GM EOS is now reformulated with less protection.
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