According to figures released by the Energy Department Dec. 30, the national average cost of diesel this week rose to $1.491 from $1.44 per gallon last week. In two weeks, the national average price has risen nearly 10 cents.

The lowest price nationally is in the Gulf Coast region. Diesel there costs $1.448 per gallon on average.

The highest average prices are found in the Central Atlantic, where the average is $1.581; in New England, where the price is $1.554; in California, where the price is $1.577; and on the West Coast, where the price is $1.54.

The remaining regions' prices per gallon are as follows: East Coast, $1.506; Lower Atlantic, $1.470; Midwest, $1.493; and the Rocky Mountain region, where prices are an average of $1.451 per gallon.

The Department of Energy reports the average price of self-serve fuel each week. Prices are based on a survey of 350 diesel service centers nationwide and include taxes.