The national average price for a gallon of diesel increased 1.7 cents to $2.489 for the week ending Jan. 29, according to the Energy Information Administration.

New England was the only region that posted a price drop, down 0.7 cents to $2.661. Meanwhile, California suffered the most extreme increase as prices spiked 5.9 cents to $2.733. California was also the most expensive region in which to buy diesel. The best pump prices were found at the Midwest, at $2.431 after a 0.8-cent increase.

For more detailed diesel price information, go to www.fleetowner.com/diesel.xls.