I was referrring to the "1999" court case. Here is one write up amongst many manyExxonMobil uses different base stocks to achieve the required performance for their products. Many are blended with GTL Group III stocks.
There was no court case.
Group III base stocks are synthetic.
http://xtremerevolution.net/a-defining-moment-for-synthetics-by-katherine-bui-lubricants-world-1999/
TBH the naming, marketing and finally the chemistry is become so complex, confusing if not misleading, I find it challenging to know what is exactly going on unless you work or worked for the company as they don't publish the ingredient list