For the first time in three weeks, average U.S. diesel and gas prices dropped, but only by less than a tenth of a cent for each. The current averages for diesel and gas are $3.848 and $3.389, respectively, down from last week's $3.854 and $3.391.

For diesel, the only two regions that didn't see a price decrease were New England, where the average diesel price rose by one tenth of a cent to $4.077, and California, where prices rose by half a cent to $4.121. As usual, California claims the highest average diesel prices in the country.

Crude oil futures settled higher this week after the European Union agreed to an embargo on oil imports from Iran starting July 1.

Light, sweet crude oil for March delivery on the New York Mercantile Exchange settled 1.3%, or $1.25 higher, at $99.58 a barrel. ICE North Sea Brent crude settled up 72 cents at $110.58 a barrel.

The EU embargo, which was widely expected, advances U.S.-led global efforts to restrict Iran's economic lifeline because of what it says is Tehran's refusal to halt efforts to gain nuclear weapons.