The administration wants to cease increasing efficiency mandates, saying that would boost auto sales. California and other supporters of stronger mandates dispute that, and want tougher standards to help lower greenhouse-gas emissions that cause climate change. California leaders responded to the Trump administration action with another pledge to defend their authority, raising the chance the disagreement turns into a yearslong legal battle and ends in the Supreme Court. The biggest auto trade groups responded with calls for talks to continue. The impasse in negotiations brings the auto industry one step closer to the scenarios it has tried to avoid: two different sets of environmental standards for cars and trucks sold in the U.S., and a lengthy power struggle over who sets them. The administration is now two years into an effort to change the rules, and faces further delays. Once slated to be finalized in late March, the overhaul […]