Prices at the pump have tumbled to multiyear lows, but don’t worry about your local gas station. When oil prices spike, so do gasoline prices, as retailers pass along the higher cost to consumers. But when prices fall, gas stations can keep retail prices higher for longer. Gasoline futures, which roughly track wholesale prices before taxes and transportation costs, have fallen 31% from mid-June to settle Wednesday at $2.1556 a gallon, near four-year lows. In the same period, the national retail average cost of gasoline fell 16% to $3.094 a gallon, according to the Oil Price Information Service. Between the wholesale and retail price sit the retailers. The difference between retailers’ net gasoline costs, including taxes and transportation, and the cost they charge at the pump rose to 36.9 cents a gallon on average last week, from 25.6 cents a gallon a month before, OPIS […]