The national average diesel fuel price decreased one cent from last week to $3.97 per gallon according to the EIA’s Gasoline and Diesel Fuel Update. The Rocky Mountain region had the only price increase for the week where the average price per gallon went up one penny from last week to $3.94. Rising less than a penny, the average price on the West Coast remained at $4.14 per gallon. The average price per gallon of diesel fuel on the East Coast, Midwest and Gulf Coast regions all decreased by one cent. The East Coast’s average diesel price decreased to $3.98, the Midwest’s to $3.95 and on the Gulf Coast it declined to $3.89 per gallon.