Several years of low gasoline prices have upended a decade-long shift towards more fuel efficient vehicles in the United States. For two years in a row, the U.S. auto industry broke new records for total sales, as an improving labor market and cheap gas induced more motorists to take to the roads. Car and trucks sales topped 17.5 million in 2016, the highest on record. At the same time, the industry is dealing with oversupply as automakers ramped up manufacturing capacity for sedans and lighter-vehicles in preceding years, which ran headlong into an era of rock bottom gasoline prices. Motorists have fallen back in love with gas guzzlers since 2014, taking advantage of the cheapest gasoline seen in years. So even as automakers are selling record levels of vehicles, they are having to offer steep discounts for sedans to unload inventory and are even temporarily shutting down production lines […]