No quicker than had the average cost of diesel fuel started heading higher it reversed course, according to new U.S. Energy Department figures.

The weekly average is down 0.4 cents per gallon, registering $3.879, 11.2 cents less than the same time a year ago. The decline follows a nearly four-cents hike the week before, the second straight increase. Prior to this the price of diesel failed to increase for nearly three consecutive months.

Over the past week diesel prices fell in all parts of the country, except in the East Coast region, as well as in two of the three sub regions that make it up, New England and Central Atlantic, with the former having the highest price of any part of the country, $4.066, up 2.6 cents over the past week, but nearly 11 cents lower than a year earlier.

The least expensive region is the Gulf Coast, down 0.7 cents over the past week, for an average of $3.773 per gallon.

Meantime, the average price of gasoline has moved lower over the past week for the second consecutive week, shedding 0.3 cents this week and registering $3.269 per gallon, 8 cents lower than the same time a year ago.

Prices fell in the Lower Atlantic sub region of the East Coast and the region overall, along with the the Gulf Coast, Rocky Mountain and West Coast regions, minus California, while it increased in all others.

Gasoline ranges between a low of $3.077 in the Rocky Mountain region, down 3.6 cents over the past week, to a high $3.494 in New England sub region of the East Coast, up 1.9 cents during the same time.

This happened as crude oil on Monday fell 31 cents by the end of trading in New York, settling at $97.34 per barrel, up around $3.50 over the past week. Before Monday the price had increased for six straight trading sessions, hitting a one-month high on Friday, following positive economic news last week, including lower unemployment figures for the U.S.