What is the "name brand" of Costco gas for gas stations in Calif.?

Question

What is the "name brand" of Costco gas for gas stations in Calif.?

Answer 1

Kirkland, just kidding. There is only really 3 gas manufacturing companys in the US, so it could be any one of the three.

Answer 2

An old CNN article describes the supply chain of Costco when selling gas, and says that Costco gets their supply from independent refiners

http://edition.cnn.com/US/9904/09/cheap....