The shale oil boom is proving far less kind to Mercedes-Benz drivers than it is to those sitting behind the wheel of a Toyota Camry or Chevrolet Impala. While regular gasoline -chugging drivers are paying just $3.04 a gallon in the U.S., the lowest in four years, those cruising around in luxury cars and demanding only the finest of grades, known as premium, have seen smaller declines. The price gap between the two grades swelled last week to the widest since 2008. Shale drilling is one of the main reasons behind the growing divergence. The record oil being pumped at U.S. shale formations tends to be more easily turned into low-octane gasoline. That’s helping push its price down more than the cost of premium fuel as benchmark U.S. crude oil sank below $80 a barrel for the first time since 2012. “You’re at their mercy; if you want to […]