After barely moving higher last week, the average cost of on-highway diesel is the U.S. has reversed course over the past week.

According to the U.S. Energy Department it is down 0.7 cent to $3.913 per gallon, its first drop in three weeks, but is still 8.5 cents higher than the same time a week ago. The average cost of diesel has been at $3.90 or higher all year, except during parts of last month and January.

Prices declined in all part of the country over the past week with the largest seen in the Gulf Coast region, 1.4 cent, for an average of $3.802 per gallon, also the least expensive part of the country.

The highest average price is in New England, down 0.9 cent from last week, at $4.098 per gallon, followed closely by the Central Atlantic and West Coast parts of the country, at just below $4.07.

As for regular grade gasoline the average U.S. price fell 2.6 cents from last week, hitting $3.678, but is nearly 17 cents higher than the same time in 2013.

Prices increased in New England, Rocky Mountain and West Coast regions, but fell in other parts of the country from last week, with the lowest price being in the Gulf Coast region at $3.462, down 2.1 cents from last week, with the highest price being in $4.037, up 0.1 cent during the same time. Like diesel, prices in all the different regions are higher compared to the same time last year.

Meantime, the price of crude oil was down on Monday as well as compared to a week earlier in New York trading. It fell 53 cents, settling at $103.53 per barrel, down nearly $2 from the same time last week as worries about supplies from the Mideast have eased and expectations that Libya will soon boost its oil exports.