Automakers Say Trump Pollution Rules Could Mean ‘Untenable’ Instability and Lower Profits

“Our thinking is, the rule is still being finalized, there is still time to develop a final rule that is good for consumers, policymakers and automakers,” said Gloria Bergquist, a vice president at the Alliance of Automobile Manufacturers.

But criticizing the president’s plan comes with risk for the automakers. The White House has courted their support for his moves, and, in particular, executives at auto companies have said they expect to be asked to stand with Mr. Trump in the Rose Garden when he announces the rollback — just as they once stood with Mr. Obama in 2009 when he announced the creation of the pollution rules.

Privately, some officials have said that they fear auto industry criticism of Mr. Trump’s rollback could lead the president to retaliate by imposing tariffs on auto imports. That, too, could be painful for the industry, because many cars and components are now made or partly assembled across the border in Mexico or Canada.

In asking Mr. Trump to rewrite his planned rollback of the pollution rule in such a way that it could be supported by the environmentally progressive state of California, the automakers effectively withdrew their support for Mr. Trump’s current plan and asked the president to make a deal with a state that he appears to relish antagonizing. Mr. Trump has variously described California as “ridiculous,” “out of control” and “the state that has wasted billions of dollars.”

Xavier Becerra, the California attorney general, has said repeatedly that the state intends to sue Mr. Trump over the weakening of the auto pollution rules. In one such remark this year, he said he was “prepared to defend our national clean car standards even if the Trump administration intends to go AWOL.”

While two of the nation’s Big Three companies signed the letter, the third, Fiat Chrysler, which has been more supportive of the administration’s plan, did not. Other automakers who signed the letter include BMW, Honda, Mazda, Nissan, Subaru and Volkswagen.