"In the debate over how quickly to make American cars pollute less, the nation’s auto-parts makers are now in open disagreement with the automakers that buy the countless transmissions, turbochargers and other components that make up modern automobiles.
Car manufacturers would like to roll back standards dating from the Obama administration that mandate a deep cut in auto emissions. The rules, which require automakers to nearly double the average fuel economy of new cars and light trucks by 2025, are the single biggest step the United States has taken to combat climate change.
Automaker groups say the Obama-era rules fail to take into account the rising demand for larger vehicles, which pollute more and make progress on overall emissions more challenging. The Trump administration is reviewing the rules for possible revision."