I think they made the switch.

[Colorado87]

I have wondered how many actual different "blends/types/brands" of gas there really are. Surely, more than a few companies use the same refinery.

There are really not that many types/brands. Each brand has a summer and winter blend as required by the EPA. As for brands each major refining company is a brand (Shell, Chevron, BP, Exxon, Valero, etc). At their name brand stations they sell their gas with their "unique" blend of detergent additives. All the non name brand stations buy fuel from one of the majors. The unbranded fuel still has the EPA required detergents, just not as much as a name brand. There are really only around 8 brands each with a branded and non-branded blend. Not much difference over all.