When you hear about the average national gasoline price, it’s often different from what’s displayed at the station down the block. So why are prices so inconsistent from station to station, not to mention state to state?

A gallon of gasoline costs about 50 percent more in New York than Missouri. Taxes vary by as much as 35 cents a gallon, according to the American Petroleum Institute. Geography plays a role, too. States like Missouri and Oklahoma are near lots of refineries, and those refineries have pipeline access to cheaper crude supplies from the U.S. and Canada. Finally, state and local regulations produce many different varieties of gasoline, with different ethanol blends, octane requirements and emissions standards.