Diesel and gasoline prices continued their nationwide decline this week, with the price for a gallon of diesel falling 3 cents on average to drop below the $4 mark.

Diesel prices averaged $3.98 per gallon nationally, falling 0.7 cents below where the price for a gallon of diesel was one year ago at this time.

According to the U.S. Energy Information Administration's weekly report, diesel prices dropped in all regions with the exception of places along the East Coast and some of the West Coast.

The most expensive diesel on average is being pumped into tanks on the West Coast at $4.13 per gallon. The least expensive diesel can be found in the Gulf Coast region where prices average $3.88 per gallon, which is 4.5 cents less than it was a week ago.

Gasoline prices also continued their downward decline and fell nationally an average of 4.3 cents per gallon to rest at $3.45. The Gulf Coast is also experience the lowest gasoline prices in the nation paying an average of $3.21 per gallon.

Crude oil prices for December also saw a decline, and settled at $85.38 per barrel. According to a Nasdaq report, "Oil prices have tumbled due to reports of ample global crude supplies and weakening fuel demand."