The national average price for a gallon of diesel fell 4.3 cents to $2.537 for the week ending January 7, according to the Energy Information Administration (EIA).

Although prices fell in all regions, the biggest drop was seen in the Midwest region, down 5.1 cents to $2.483. Prices held the steadiest in the Rocky Mountain region, falling only 1.5 cents to $2.682. California was once again the most expensive region in which to purchase diesel at $2.856 on a 2.7-cent drop. The cheapest region in which to fill up was the Gulf Coast at $2.459 after a 4.1-cent decline.

For more information, go to http://tonto.eia.doe.gov/oog/info/wohdp/diesel.asp