ENEOS oil: power adder or snake oil?

[Halon]

I was going to write the whole lawsuit thing in my own words, but found it easier to just copy and paste this directly from the AMSOIL site.

Several years ago Mobil accused Castrol Syntec of reformulating its synthetic by substituting other basestocks in place of its synthetic polyaphaolefins (PAO's) using hydroprocessing oil. Castrol has replaced the PAO synthetic base stock with hydroisomerized petroleum base stock. Hydrocracking, as it's called, is the highest level of petroleum refining. Castrol Syntec is not a Group 4 synthetic (such as AMSOIL is) yet Castrol ended up winning the battle when the National Advertising Division of the Council of Better Business Bureaus ruled that Castrol could still market its oil as "synthetic" despite their new formulation. Basically, they expanded the definition of synthetics to include Group 3 hydroprocessed petroleum oil. This high profile case took place because synthetics are recognized as the market's best hope for growth. Synthetic oil sales have outpaced petroleum oil sales by a wide margin and the gap continues to widen every year. Consumers are getting smarter and demand the best for their vehicles. Read the full story on the Castrol issue in our informative articles section. Additionally, just as soon as Castrol won this battle, several other oil companies came up with hydroprocessed motor oils of their own and labeled these products to be "100% synthetic", when they still are Group 3 hydroprocessed petroleum oils and not full PAO Group 4 synthetics.

So in a nutshell, Mobil was pissed because they were using a Group 4 synthetic base in their synthetic line, while Castrol was simply using a Group 3 highly refined petroleum base oil in their synthetic line. Castrol won, so now a lot of the off the shelf synthetics you'll find at the store are now using Group 3 base oils as well.