Diesel prices have now declined for the sixth week in a row. For the week ending Dec. 12, the U.S. average diesel fuel price fell 21.3 cents from the previous week to $4.754 per gallon, the U.S.Department of Agriculture said. That's 110.5 cents above the same week last year.

This week’s decline marks the largest since Oct. 13, 2008, the USDA said, when the diesel price dropped 21.6 cents near the start of the global financial crisis. Also, this week, the diesel price was the lowest since Oct. 3, when it was $4.836 per gallon. In the grain-producing Midwest, the diesel price dropped 25.6 cents to $4.651 per gallon, the lowest price this year since March 7, the USDA said.