Hundreds of millions of vehicles’ worth of pollution will be erased by 2025 under gas mileage standards passed by the Obama administration.

That’s far less smog-inducing pollution making worse the asthma and other lung ailments too frequent in Maine, and contributing to the climate change that is rising seas along the Maine coast, rapidly changing the Gulf of Maine, and altering the composition of our forests.

And the standards are expected to save drivers more than a billion dollars in fuel, and pump up domestic manufacturing as well.

All along, the auto industry proved it could make cars that are better for the environment, as long as they had the incentive.

This week, however, the Trump administration is set to take that incentive away, as the Environmental Protection Agency is expected to announce it is rolling back the Obama-era standards, which when enacted in 2012 called for the average miles per gallon of new vehicles to double by 2025.

The move would certainly draw a response from the state of California, which for years has had the ability to set its own mileage and emissions standards, and has done so with an eye toward cutting pollution and the use of fossil fuels. Twelve other states, including Maine, now follow California’s lead.

Automakers have decried having two standards — one for California and like-minded states, and one federal. Some even are asking for the EPA to revoke California’s waiver.

Whatever the case, loosening the standards in any way would slow the impressive gains made over the last few years, and have profound effects on air quality in Maine.

Car makers have made a lot of headway on gas mileage in the last decade-plus. The average fuel economy for car-based SUVs went from 20 miles per gallon in 2005 to 25.3 mpg in 2015. Truck-based SUVs in the same period went from 16 mpg to 22 mpg.

Overall, gas economy hit a record high average of 24.7 mpg in 2016, with another record expected once 2017 numbers are finalized.

The actions taken by the Obama administration beginning in 2012 and extending through 2025 are expected to cut emissions so broadly that it would be the equivalent of taking 422 million cars off the road. Drivers are expected to save $1.7 billion in fuel costs, while oil consumption would be cut by 12 billion barrels.

The pursuit and fulfillment of the Obama-era standards will not only cut the amount of greenhouse gases released into the atmosphere, with the goal of curtailing the climate change that affects Maine is so many ways, it will also make Maine’s air cleaner.

A receiver of pollution from the coal-fired plants of the Midwest and heavily trafficked cities of the Eastern Seaboard, Maine suffers when other states do not take action against emissions. Under administrator Scott Pruitt, the EPA has taken aim at the measures that protect Mainers, arguing against the Clean Power Plan, which controls power plant emissions, and refusing to enforce strict ozone standards.

Now comes the shot against standards for car emissions — the largest contributor to Maine pollution. Automakers say the Obama-era rules are stifling, but they have had no little trouble advancing technology to meet them, and car sales have not suffered at all.

Cutting the standards, though, would certainly please automakers. It would also be on-brand for Pruitt, who doesn’t buy the clear science on climate change and as EPA head has consistently backed industry over the environment. But it would do nothing but hurt Mainers.