fuel efficiency

The Trump administration is replacing Obama-era fuel economy standards with weaker ones that will allow for more air pollution. Groups are already lining up to challenge the new rule.

The lawsuit comes two days after the Trump administration revoked California's ability to set its own rules for automobiles. The state's top prosecutor blasted the move as "arbitrary and capricious."

The end of the state's Obama-era waiver is seen by many as the latest move to undo a years-long push to produce more fuel efficient cars.