The national average price for a gallon of diesel jumped 3.4 cents to $2.98 for the week ending June 30, according to the Energy Information Administration (EIA).

All regions posted an increase except for the one that needed a price break the most—California. In spite of a 0.4-cent decrease, California still was the most expensive region in which to fill up at $3.097. The Rocky Mountain region saw the biggest price shock on a 6.5-cent increase to $3.052.

The Lower Atlantic region was once again the cheapest in which to fill up at $2.924, after rising 3.6 cents.

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