Americans are paying the least to fill their cars in almost two years as refiners process the most crude in a decade, offering some relief to nervous consumers. The national average retail price sank 1.1 cents to $3.211 a gallon, the lowest since Dec. 20, 2011, AAA, the nation’s largest motoring club, said on its website today. Pump prices are approaching the lowest level since February 2011, just before unrest in the Middle East pushed U.S. crude oil above $100 a barrel and gasoline near $4 a gallon. “We’re probably just a few days away from seeing the cheapest gas prices since February 2011,” Michael Green , a AAA spokesman in Washington , said by telephone. “Our official estimate would still be that we’re going to drop to $3.10 a gallon by the end of the year. At the rate we’re going, it wouldn’t be surprising if we even […]