The national average price for a gallon of diesel increased 1.5 cents to $2.491 for the week ending February 18, according to the Energy Information Administration.

All regions saw prices go up except California, which posted a 0.4-cent drop to $2.901. In spite of the slight rollback, California remained the most expensive region in which to fill up. The Gulf Coast retained its claim for having the cheapest diesel even after it posted the largest jump, up 2.4 cents to $2.418.