I was browsing through the conoco phillips web site and learned that they formulate Mazda synthetic motor oil and also produce some of the John Deere motor oil. What was most shocking was that the group lll oils they refine are not made in the old U.S. but in South Korea
This group 3 product would go into the mazda synthetic oil and the motorcraft synthetic oil and their own synthetic oil. I am sure thy sell this base stock also. Kind of a shame they have producton in other countries- but I guess that is how most all companies tend to keep costs lower.