Mobil did not sue (which by definition requires trial in open court and generally includes the provision of monetary restitution) Castrol. The matter was settled through binding arbitration through the National Advertising Division of the Better Business Bureau. There was NO monetary judgment. The issue centered on whether the definition of "synthetic" extended to Group III base oils which undergo considerable upgrading at the molecular level during severe hydroprocessing under high heat and pressure in a closed environment. Mobil's position was that PAOs, which are built from simple hydrocarbons into the desired molecualr configuration through repeated (and costly) polymerization steps, are the only true synthetic base oils derived from underground hydrocarbon sources. Castrol, and a number of industry competitors, feel that cracking and re-constituting to a purer, consistent molecular weight paraffin* content through isomerization also legitimately qualify as a form of synthesis. The arbitrator agreed with Castrol's position after testimony was taken from academic and industry expert witnesses. But, don't feel sorry for ExxonMobil, they were, and still are, one of the world's leading purveyors of Group III base stocks as well as the technology to, er, synthesize them. They've cried all the way to the bank before and since the arbitrator's gavel stopped echoing.
*Lest anyone persist in his lovingly embraced delusion that "paraffin" equates to "wax", NONSENSE and HORSE PUCKY! Waxes are only one TYPE of molecule under the general class of hydrocarbons identified as paraffins. Under hydroisomerization, the parrafin wax molecules are "broken" and reconstituted into the desired chain length paraffin oil molecules. This also happens with undesirable aromatics present. The end result are base oils that can exceed a VI of 140 - and this is definitely in PAO performance territory in lubricity, pour point, flash point, and oxidation resistance. While some contaminants inevitably persist due to the economics of keeping the hydrocooker percolating (the old "Law of Diminishing Returns" comes into play here), they're well down into the low, single digit percentages. Pure paraffins polymerized (NOT isomerized in this case) from methane gas in "gas-to-liquid" processes due to be a commerical reality by the end of the decade will surprise a lot of people.
[ June 09, 2005, 10:56 AM: Message edited by: Ray H ]