The national average retail price of a gallon of diesel plummeted to $4.207 in the past week, according to the U.S. Energy Information Administration.

The EIA's weekly price recap shows the average price fell 14.6 cents from last week's $4.353.

The highest prices were found in the New England area, where they averaged $4.422; the lowest in the Midwest at $4.13.

This is the fifth week in a row prices have fallen, from a high of $4.764 on July 14.