The average diesel price nationally fell 1.1 cents this week, according to figures released by the Department of Energy.
The price fell from $1.628 to $1.617. The biggest drop came on the West Coast - 4.4 cents, from $1.845 to $1.801 - but it remained the highest-priced diesel in the U.S.
The Rocky Mountain region was the only region with an increase - 1.3 cents to $1.636.