The national average price for a gallon of diesel increased 0.3 cents to $2.621 for the week ending December 10, according to the Energy Information Administration.

Not all regions posted a price hike, however, with the Midwest posting the steepest drop, down 1.5 cents to $2.563. Conversely, the steepest increase was in California, up 10.3 cents to $2.963. California was also the most expensive region in which to fill up. Bargain hunters should look to the Gulf Coast region, even after a 0.3-cent increase to $2.54.

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