The world’s largest automakers warned President Trump on Thursday that one of his most sweeping deregulatory efforts — his plan to weaken tailpipe pollution standards — threatens to cut their profits and produce “untenable” instability in a crucial manufacturing sector. In a letter signed by 17 companies including Ford, General Motors, Toyota and Volvo, the automakers asked Mr. Trump to go back to the negotiating table on the planned rollback of one of President Barack Obama’s signature policies to fight climate change. The carmakers are addressing a crisis that is partly of their own making. They had sought some changes to the pollution standards early in the Trump presidency, but have since grown alarmed at the expanding scope of the administration’s plan. Mr. Trump’s new rule, which is expected to be made public this summer, would all but eliminate the Obama-era auto pollution regulations, essentially […]