The average price for a gallon of diesel nationally fell by 1.5 cents to $2.606 for the week ending December 17.
All regions posted a decline. Prices fell by 0.8 cents in the Central Atlantic, Midwest and Rocky Mountain regions, to $2.722, $2.555 and $2.716, respectively.
California experienced the biggest drop (4.6 cents), but remained the most expensive region at $2.917. The Gulf Coast was the cheapest at $2.519 after a 2.1-cent decrease.