Well this is a plot twist.
In early 2017 just after Trump had just become the president of the United States, 18 different automakers got together and signed a letter asking the new commander-in-chief to weaken fuel economy standards. The idea was simple: Obama-era regulations would mean car companies would have to spend billions developing fuel-efficient engines and electric vehicle technology, and they simply didn't want to pony up.
The president complied, going as far as to propose a new rule that would freeze mileage standards at 37 mpg by 2025, down from the Obama rule's 54.5 mpg target by the same year. But in a twist of fate, 17 automakers, including Ford, General Motors, Toyota and Volvo, have now signed a letter asking the president to put a halt to that rule, claims the New York Times.
Their reasoning doesn't stem from a change of heart and a desire to save the planet, it's because the president's ruling has been met with a promise from 14 states that each would enforce a stricter standard and simultaneously sue the Trump administration in order to get back Obama's EPA rules. That's because for automakers, having two separate fuel economy guidelines within one country is a nightmare scenario.
It would mean the US market would effectively be split in to, with different regulatory thresholds making it so that new cars sold in certain states following the Trump administration's ruling could not be sold in states with their own stricter standards. Moreover, a lawsuit could complicate the issue further by casting future fuel economy standards into uncertainty, which is a huge problem for companies that plan their product lines many years in advance and must know what standards they need to meet well before production begins.
The ideal scenario for the auto industry would be if the Trump administration and the states looking to enforce their own standards meet and agree on a single standard for the entire country. In order to push that narrative, automakers also sent a letter to California's Governor Gavin Newsom, seeking a standard that is "midway" between the current Obama rules and Trump's proposed cuts.
The letter to Trump simply asked the president to consider working with the states that want stricter standards in order to reach an agreement that would set only one fuel economy standard for the country. "We strongly believe the best path to preserve good auto jobs and keep new vehicles affordable for more Americans is a final rule supported by all parties - including California." But given that both sides are deeply rooted in their positions, that kind of compromise may not happen.