Viscosity is set by SAE, so it should be what's on the quart. It is set through a math formula that determines what the viscosity is. The European oils have a grading system through ACEA, that is comparable to API on our side of the pond here. That is the difference I believe you are hearing about, though I could be wrong, it happens
http://techmax.ca/european_import_ca...ifications.htm
in reference to the two standards of grading. I may be wrong about viscosity, I think your SA was trying to tell you the difference between 5w oils and 0w oils is negligible, and should not be something to fret over.
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