Oh right, I had forgotten about that. The whole thing is silly, really. What is it at any one time we have. . 41 different fuel formulations? I think it's 41. Someone Google that.

There's also the break between unleaded and diesel. Mutually exclusive in the refining process. I think it was last in 2006-2007 that diesel was continually cheaper while regular was creeping to 4+ because the refineries guessed wrong.