Reason No. 1: People are driving less
It happens every year after Labor Day. Summer vacations end, temperatures drop, beaches and amusement parks close for the season. The net result is Americans have fewer reasons to hit the highways.
That means they'll buy less gasoline. And when consumers need less gasoline, prices tend to fall.
In the U.S., gasoline consumption almost always declines from the third to fourth quarters. From 2002 to 2012, for example, consumption declined by an average of 2.7 percent from the July-September period compared with the October-December period, according to a Bankrate analysis of government petroleum data. A drop in consumption is expected this year as well.
In addition, the decline in winter gasoline consumption recently has been accompanied by a general decline in U.S. demand. Americans are not only driving cars and trucks that are increasingly fuel efficient, they're also driving less.
Overall, gasoline demand in the U.S. has declined every year since 2007.