The Trump administration is making a big mistake messing with clean cars. Here are 5 reasons why.

Editor’s note: This post was updated on July 23, 2018.

Our clean cars standards – a win-win policy that reduces pollution while saving Americans money at the pump – are at risk, and the Trump administration’s attempt to roll them back has already spurred a multi-state legal challenge.

Even the U.S. Environmental Protection Agency’s own Science Advisory Board has recommended a review of the underlying analysis and justification for this controversial decision. Yet, the administration is poised to go even further, attacking not just federal clean car standards but also state leadership on clean cars.

There are many reasons this counts as one of the worst attacks on our climate that this government has made to date.

1. It’s the biggest step America’s taken to cut climate pollution

The clean car standards would reduce America’s greenhouse gas emissions by a whopping 6 billion tons over their lifetime, along with other dangerous air pollutants. Transportation contributes more greenhouse gas emissions than any other sector in the nation, and the Trump administration’s rollback would significantly lower our ambition to tackle this pollution.

It’s why the American Lung Association and 12 other public health organizations have urged the agencies involved with the rollback to just drop it [PDF].

“Since the adopted standards are well within reach,” they noted, “no reason exists to alter them.”

2. Millions of Americans save money with clean cars

Over the lifetime of the historic clean car standards the federal government adopted in 2012, American families and businesses are expected to save more than $1 trillion. That’s not a typo.

A study [PDF] released July 23 shows that an average family could spend as much as $500 more each year if the standards are rolled back, with low-income and long-commuting Americans being hit especially hard.

Indeed, drivers are already benefiting from the rules that have gone into effect so far.

Tell EPA: Rolling back these standards is the wrong move.

Because the clean car standards spur improvements in fuel economy, a Ford F-150 truck bought in 2015 uses about 180 fewer gallons of gas a year than earlier models, for example. That saves its owner eight trips to the gas station and enough money each year to easily cover a monthly car payment.

Such improvements also help insulate American families from the volatility of gas prices, which have risen nearly 50 cents per gallon on average over the past few months.

3. There’s no burden – we can already exceed these standards

Since 2012, we have roughly doubled the number of SUVs that get 25 miles per gallon or more, of cars that get 30 miles per gallon or more, and of cars that get 40 miles per gallon or more.

There are already more than 100 car, SUV and pickup models on the market that meet standards set for 2020 and beyond. In fact, technical reviews show that carmakers can meet the 2020-2025 model year requirements at a lower cost than first predicted. This isn’t rocket science, as other nations can attest.

4. This attack would undermine state leadership

A coalition of 17 states and the District of Columbia, together representing more than 40 percent of the U.S. car market, have already sued the EPA to challenge the agency’s final determination to weaken the standards.

For decades, states have had authority to enforce more protective standards to address tailpipe air pollution problems than the federal government did. The Trump administration is now on a collision course with such states after a leaked draft of the clean car roll-back proposal showed that the administration is also planning to attack that state authority.

5. Even industry is concerned Trump has gone too far

As news of Trump’s proposal began to leak out, leading car manufacturers Ford and Honda highlighted the importance of working with state clean car leaders. What we need is “one strong national standard for our industry,” Honda wrote. A coalition of large automotive component suppliers also raised concerns.

And electric vehicle manufacturers Tesla and Workhorse are among a diverse coalition that just filed suit to oppose Pruitt’s final determination to weaken existing clean car standards.

It appears that very few people, when it comes down to it, want dirtier cars.

Tell EPA: Rolling back these standards is the wrong move.