Exxon-Mobil base stocks are the only ones that can make SN+ with group II.
How do you know this? I've seen this mentioned a few times.. what exactly does this mean? Are you suggesting Chevron or Conoco (for example) grp2/2+ base stocks can't meet API (SN)+ requirements and that they're are buying from XOM??.. I find that hard to believe because what blender would buy Chevron grp2 stocks?
And correct me if I'm wrong a change in base stock isn't needed to meet SN+ from API SN since calcium has been identified as the main antagonist to LSPI, so a rebalancing of Cal/Mag has been the preferred
approach to passing the Sequence IX test to gain SN+ approval, right???
*some lube mfgs take a slightly different approach to addressing lspi by use also of moly and titanium chemistriesPQIA - LSPI