Americans could stand to save up to $1.1 trillion on gasoline prices should the Environmental Protection Agency's proposal to impose the toughest-ever auto emissions standards be adopted, the agency projected on Wednesday.

The projection was included in the 758-page report issued by the EPA detailing its proposed regulations, which include tailpipe emissions so stringent that it could lead to 67% of new vehicle sales being electric by 2032.

Such a big shift to electric cars could save Americans between $580 billion and $1.1 trillion on gasoline — even factoring in the extra money drivers would spend on electricity to juice up their vehicles.

The agency forecasts an additional $280 billion to $580 billion in savings on vehicle maintenance.

The EPA predicts that U.S. consumption and net imports of petroleum would both go down as a result. That would increase U.S. energy security, although as the EPA acknowledges, the U.S. is now also a major oil producer — in fact, the world's largest oil producer.

Trade groups representing U.S. oil and gas producers have joined a legal challenge against EPA's previous efforts to promote electric vehicles.

In legal filings, they wrote that their members would suffer "material adverse consequences" from a shift toward electric vehicles, which would also hurt the coffers of oil-producing states like Texas.

Multiple domestic oil groups declined NPR's requests for comment.

EPA also projects other big savings for car owners

EVs are cheaper to operate than conventional vehicles; the exact amount of savings depends on local gasoline and electricity prices. But they cost more up front.

And a similar pattern holds in the EPA's analysis. If the proposed standards are put in place, the EPA estimates every car sold in in 2032 will cost $1,200 more to manufacture than it would otherwise.

That price increase, however, would be canceled out by the savings on fuel, cost and maintenance, so that overall, an owner of a car or SUV would save $9,000 and the owner of an electric pickup truck would save $13,000, according to the EPA.

The switch to EVs could have benefits for broader society, too: fewer premature deaths from road pollution and reduced impacts of climate change. The transportation sector is the largest source of planet-warming emissions in the U.S., which is the world's biggest consumer of oil.

The change being envisioned here is big — really, really big.

"This reinvents the vehicle," says Michelle Krebs, executive analyst at Cox Automotive. "It reinvents how consumers interact with their vehicle. It reimagines the entire industrial base."

Thomas Boylan, the regulatory director at the Zero Emissions Transportation Association — a trade group representing companies along the EV supply chain, which stands to benefit from this transition — noted that the industry has a few years to prepare.

"The investments that are being made today, of which there are very many, ... they are going to bear fruit over the time period that these standards contemplate," he says. "I think there's going to be a very different world come 2027."