The biggest plunge in U.S. gasoline prices since 2008 is slowing as higher ethanol boosts the cost to make the motor fuel.
Ethanol futures surpassed gasoline last month for the first time since March. Faced with higher costs, refiners and blenders used the least ethanol in a year last week. Pump prices have slipped 6.6 cents in the past week, the smallest drop in a month, according to AAA.
