The battle over California’s vehicle fuel economy standards and greenhouse gas regulations could impact your personal budget.

The Trump administration contends that freezing fuel economy standards will reduce the average sticker price of new vehicles by about $2,700 in just a few years. Its embroiled in court action to prevent California from continuing to impose stricter guidelines than the federal government.

And now, GM, Fiat Chrysler, Toyota, and several other automakers are siding with the administration in an ongoing lawsuit over whether California can go it alone with its own rules.  The automakers' group, called the "Coalition for Sustainable Automotive Regulation," also includes Nissan, Hyundai, Kia, Isuzu, Maserati, McLaren, Aston-Martin and Ferrari.

The automakers agree with the administration that one set of federal rules makes more sense. Up until yesterday, those automakers have sat on the sidelines as California and federal lawyers duked it out in court.

California has 35 million registered vehicles, the most of any state. A dozen other states and the District of Columbia also follow California's fuel economy standards.