The national average price for a gallon of diesel dropped 4.8 cents to $2.867 for the week ending June 25, according to the Energy Information Administration.

All regions posted a price drop, with the Rocky Mountain region posting the largest at 5.8 cents to $2.96. Prices remained the most stable in New England, with only a 0.8-cent fall to $2.952. The cheapest diesel could be found in the Lower Atlantic region at $2.816 after a 5.1-cent drop. California remained the most expensive region in which to fill up, despite a 4.5-cent slide to $3.14.

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