Despite his attempts to jettison Joe Biden’s EV mandates, President Donald Trump might have inadvertently set the stage for one of his own.

Welcome to the upside-down world of federal government fuel economy standards.

Amid the government-created “energy crisis,” a Democratic Congress passed, and President Gerald Ford foolishly signed, a law in 1975 that dictated the average fuel economy automakers must reach for the passenger cars they sell in a given year. Failure to meet that standard meant paying huge fines.

The energy crisis is long gone, but the federal “Corporate Average Fuel Economy” (CAFE) standards live on. And, as with any regulation, it metastasized into an enormously complicated and expensive pile of rules. Barack Obama and Biden both tried to use CAFE as a backdoor EV mandate.

Since taking office, Trump has taken several big steps toward liberating the auto industry from this monstrosity. Last December, he proposed a significant rollback of Biden’s super-strict CAFE standards. He signed a law eliminating the fines for violating those CAFE standards. He overturned a rule that gave the EPA carte blanche to regulate carbon emissions from cars. And he ended the massive taxpayer subsidy for EV sales. (All of which we celebrated in these pages.)

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But we recently learned about another, largely overlooked, rule change that could still end up acting like an EV mandate.

Here’s why. One of the many complicating factors in setting CAFE standards was what to do with electric cars? More than 20 years ago, government bureaucrats had decided that an EV got the equivalent of 330 miles per gallon. This is called the “petroleum equivalency factor.”

It was a ridiculous claim with no basis in reality, but it turned out to be an escape valve for automakers.

“Even if automakers produced relatively few EVs, they would still get an outsized credit that could offset an otherwise inefficient fleet,” notes an in-depth article in E&E News.

Think of it this way: if you sold one EV for every 99 gasoline-powered cars that got 15 miles per gallon, your “average fuel economy” would be 18 mpg. (Another escape valve was the classification of SUVs and minivans as “light trucks,” which are a separate category from passenger cars and face far less restrictive CAFE standards, and which wildly distorted the market, but that’s another story.)

In its determination to force EV sales, the Biden administration decided to cut the “petroleum equivalency factor” by a third — dramatically shrinking this escape valve — while sharply raising the CAFE standard to 50 mpg by 2031. To comply, automakers would have no choice but to shift their fleets almost entirely over to EVs — regardless of what consumers wanted to buy.

Well, lawsuits ensued, and a federal appeals court ruled in 2025 that the Biden change was illegal, so the “petroleum equivalency factor” went back to 330 mpg.

But then Trump’s Energy Department “abruptly cut that credit by 85%,” E&E News reports. “EVs were now assumed to get about 50 mpg equivalent, roughly on par with many plug-in hybrid models.”

While 50 mpg is probably a more realistic comparison, the result could be to force automakers to quadruple their EV sales, according to E&E News.

We don’t know whether that concern is legitimate, but we do know that if Democrats regain control of the White House and Congress, this much lower “petroleum equivalency factor” would make it far easier to impose draconian EV mandates in the future.

So, what’s the answer? Well, the Trump administration could find a way to boost the “petroleum equivalency factor.” Or it could lower the CAFE standards still more. Or it could tweak other parts of the rules to lessen the burden on automakers and car buyers.

But there’s a much simpler solution.

Trump and his fellow Republicans need to scrap CAFE altogether. Repeal the law. Eliminate the regulations. Rip it out, root and branch. Then poison the soil. And in doing so, make it clear that the government has absolutely no business whatsoever dictating to car companies what the average fuel economy of the vehicles they sell must be.

Because otherwise, no matter how much trimming is done, CAFE will eventually reemerge, bigger and more harmful than ever.

–  Written by the I&I Editorial Board