Supreme Court Shakes Up Diesel Industry with Chevron Doctrine Reversal

Chevron Doctrine Overruled—What It Means for the Diesel Industry

Photos by DW staff

In June of 2024, the Supreme Court voted 6-3 to overrule the Chevron Doctrine. Immediately, diesel enthusiasts around the country started celebrating—or trying to figure out what the heck that means.

If you’re not familiar with the Chevron Doctrine, in a nutshell, it grants federal agencies (the EPA, in this example) to enforce their interpretation of ambiguous laws. Meaning, if Congress hasn’t outlined how a particular rule is to be followed, the court system will act on what the EPA tells them the rule means.

So, how does all that gibberish affect the diesel industry? I’m glad you asked.

“What it did change, is the EPA’s power to wield laws as they see fit.”

The Downfall of Racing

Unless you’ve been living under a rock, you’re aware that the EPA has been fining, arresting, and suing members of the racing community for well over a decade for violating the Clean Air Act.

This is where the Chevron Doctrine has (until now) played in their favor. See, the language in the Clean Air Act, as it relates to racing parts and vehicles, is a little ambiguous—a fact the EPA used to their advantage.

And by “racing parts”, we’re referring to the products that allow or require the removal of emissions equipment.

The Clean Air Act was (is) so ambiguous about whether “racing parts” were legal, that companies fearlessly sold them for decades. Everything from catless downpipes to longtube headers to custom tuning—anything meant for competition use that allowed the removal of emissions systems.

But, it wasn’t until the last 10-15 years that the EPA started taking a closer look at the racing industry. Why they decided to wait so long is hotly debated—but the effect was obvious.

Nearly overnight, hundreds of shops, brands, and tuners found themselves in court with the EPA.

With little warning, the EPA decided to reinterpret (Chevron Doctrine) the Clean Air Act in such a way that made manufacturing, selling, or installing “racing parts” a federal crime. And, since the court system was relying on the EPA’s opinion of what the laws meant, there was little that could be done.

Put simply, if the EPA accused you of violating the Clean Air Act, you were guilty. But, now that the Chevron Doctrine has been struck down—the winds seem to have shifted.

So, Are Deletes Legal?

No matter what you read in Facebook groups, as of July 2024, removing your DPF, EGR, and DEF systems is not legal in the United States.

The elimination of the Chevron Doctrine is a good thing—but make no mistake, it didn’t change everything overnight.

What it did change, is the EPA’s power to wield laws as they see fit. In theory, the Supreme Court’s decision could (emphasis on could) open the door for “race parts” to be legally sold and distributed without fear of a felony.

To be clear, this is a win for racing companies, teams, and owners. The Chevron Doctrine reversal is not intended to make it legal to “roll coal” on the streets of your hometown. In reality, that type of bad behavior is partly why the EPA came after “race parts” in the first place.

“Right now, the Supreme Court’s decision simply represents hope…”

Hope for the Future

Right now, the Supreme Court’s decision simply represents hope—hope for the racing industry, hope for our freedom to modify vehicles as we see fit, and hope that three-letter agencies won’t be able to selectively enforce laws as they see fit.

The legal status of “race parts” and the future of our industry is changing every day—so we’ll report back to you as we learn more.