One other thing to keep in mind about gas prices. Since we're a republic made up of 50 states, each can require their own gas blends. We've not built any refineries for many, many years, so the cost of refining gas blends for each states requirements gets very spendy.

Not to mention how each states define their own gas taxes to be used in the "general fund". That raises prices as well.

The other thing to watch for, is the new gasahol blends are super hard on rings and gaskets for vehicles not designed for them. I think particularly hard on home equipment, like lawn mowers, etc. The alcohol will turn them to goo.

Just MHO

I have friends that work at the petroleum pumping station in Junction City Wisconsin (Koch Petroleum). This station pumps to, I believe, 9 of the Midwestern states.

They tell me that the "blends" are done by pumping from multiple tanks of standard grades at the same time and not done at the refinery level.
The standard blends are viewable here if you're interested.

I think Tofu, that by 'blends' she may be referring to
what 'additives' each state allows.

Same thing. You should see what these pumping stations look like. Dozens of huge tanks and hundreds of pipes with hundreds of valves. All the additives are done there at the pumping station.

All the blends (including the additives) are computer controlled. Also much of the content of gasoline is also controlled by the EPA so state's don't have that much leeway to play around with the recipes.

I'll have to get one of my friends at the station to give a good description of how the inner workings go. They gave me a tour of the place once but that was before 9/11. Now I don't know if I'd be allowed in there again. Neat place though.

They have concentrated mercaptan there for adding scent to propane and methane. One fluid ounce to a 10,000 gallon tank. Stinky stuff. Kurt (one of the friends that works there) got some spilled on his clothes. His wife made him wash outside in the hose and burned his clothes.