The average price for a gallon of diesel nationally dropped 0.5 cents to $2.676 for the week ending March 25, according to the Energy Information Administration (EIA).
The biggest drop came in the Midwest region -- 1.1 cents to $2.655. The biggest increase came in the Rocky Mountain region -- 1.5 cents to $2.780.
The cheapest region was the Lower Atlantic at $2.630 after a decrease of 0.1 cents. California remained the most expensive region at $2.869, despite a 0.6-cent drop.