Originally Posted by
goehm
Hey Bob, why is this? CST is supposed to be an industry standard measure. It seems PTRC should remove their CST ratings if they really aren't using that scale, or perhaps adjust their ratings so that it aligns with their actual CST viscosity.
I'm leaning towards their values are correct and the others aren't. PTRC oils are the same as Mugen, Core, and most of the oils you see from the EU manufacturers. The only ones that appear to not follow the same standard are AE and TLR.