The gasoline market pretty much baffles me.
Don't feel bad, it's even baffling to people who make their business in the market.
Something that most people don't realize is the impact that environmental regulations have, especially if you live in an ozone non-attainment area which is almost every big metropolitan area in the U.S.
In winter, refiners can add a lot more volatile components, e.g. butanes, pentanes, etc to gasoline, but in the summer vapor pressure requirements are lowered and it becomes more expensive to produce a gallon of gasoline as these volatiles, which come with crude, have to be dealt with in other ways than blending. Oxygenates help engines burn cleaner, but the best one, and most common - MTBE - was banned a few years ago because, even though it's not really very toxic, some leaked into Lake Tahoe from underground storage tanks that should have been replaced. Now, congress in its infinite wisdom has enacted the Energy Independence Act and mandated more ethanol be blended into gasoline each year.
So if you try to understand the gasoline market from a Free Enterprise point of view, it won't work. Too much government intervention.
