EPA targets truck emission rules

After killing California’s stricter truck emission rules, the Trump administration took an even bigger swing at federal regulations dealing with heavy-duty tailpipes.

This summer, the Environmental Protection Agency began two actions that virtually the entire trucking industry applauded. One goes after greenhouse gas emission rules. Another deals with diesel exhaust fluid (DEF).

2009 endangerment finding

The first move the EPA made was a sweeping one that could undo nearly 15 years of vehicle emission regulations.

Standing in an Indiana Kenworth dealership, EPA Administrator Lee Zeldin announced the agency would start the process to withdraw the 2009 “endangerment finding.” That single document has been the foundation of emission regulations since it took effect in 2010.

In 2007, the Supreme Court ruled that the EPA could regulate greenhouse gases under the Clean Air Act. Before the agency could move forward with doing just that, it had to prove it was necessary.

Two years later, the EPA finalized a rule that determined greenhouse gases pose a danger to public health and welfare. Known as the 2009 endangerment finding, the rule would be the legal justification to regulate greenhouse gas vehicle emission, something the EPA could not do before.

Formerly a solid foundation for vehicle emission regulations, the endangerment finding can suddenly turn into a house of cards if withdrawn, taking down all of the rules that rely on it. That includes the “Greenhouse Gas Emissions Standards for Heavy-Duty Vehicles – Phase 3.”

Finalized last March, the Phase 3 rule set strict emission standards for heavy-duty trucks from model years 2027 to 2032. By 2032, 25% of sleeper cab tractors must be zero-direct-emission.

Trucking groups have criticized the new rule, claiming the mandates are unworkable. Todd Spencer, president of the Owner-Operator Independent Drivers Association, called the truck emission standards an “assault on small-business truck drivers.”

During a public hearing, OOIDA Executive Vice President Lewie Pugh welcomed the rollback of “nearly 20 years of overly burdensome emissions regulations.”

“These rules have put truckers out of work, hurt small-business competitiveness and discouraged owner-operators from purchasing new equipment,” Pugh said.

The comment period on the proposed rule to rescind the endangerment finding ended on Sept. 22. As of early September, more than 80,000 comments had been submitted, the vast majority of them mass comment campaigns from organizations opposing the rule.

EPA vs. DEF

Although DEF rules do not rely on the endangerment finding, the EPA addressed the issue separately.

To stay compliant, manufacturers have programmed trucks to derate the engine if a DEF issue is identified. In some cases, a heavy-duty vehicle can be forced to suddenly crawl at 5 mph if the issue is not resolved within four hours.

Calling the current DEF system “unacceptable,” Zeldin has issued new guidance that urges manufacturers to inform truck drivers about a DEF problem with a warning light and nothing more for 650 miles or 10 hours. This would allow long-haul drivers a full workday to fix the problem.

After that, engine torque would drop by 15%. This small reduction should not significantly affect a truck’s top speed. If the problem remains unresolved after 4,200 miles or 80 hours, the engine would be derated by 30%. After 8,400 miles or 160 hours, the truck’s maximum speed would reduce to 25 mph.

Truck drivers applauded the changes. The Owner-Operator Independent Drivers Association said the new “commonsense” schedules will help drivers maintain safe control of their vehicles as they fix a faulty DEF/selective catalytic reduction (SCR) system.

“More flexible inducement speeds and times will help truckers finish their trips, plan for necessary maintenance and avoid parking their truck for an extended period simply because of a false alarm,” OOIDA President Todd Spencer said in a statement. “Nonsensical inducement rules have sidelined small-business truckers for too long, and this accelerated relief shows what can be achieved when regulators hear directly from the people doing the job. We look forward to continued engagement with Administrator Zeldin and his staff to implement additional emissions solutions that better reflect the realities of trucking.”

OEMs vs. CARB

Despite losing its authority to enforce Advanced Clean Trucks and other truck emission rules, the California Air Resources Board is trying to do exactly that.

In 2023, original equipment manufacturers (OEMs) signed an agreement called the Clean Truck Partnership. That pact with CARB requires OEMs to follow California’s vehicle emission standards even if they are invalidated.

Now that those rules have been overturned, California is trying to enforce the deal. So far, that’s not going well for the Golden State.

Daimler, International, Paccar and Volvo are now suing California, claiming the agreement is unlawful. The lawsuit was filed shortly after OEMs received a cease-and-desist letter from the Department of Justice ordering them to ignore the Clean Truck Partnership.

Around the same time, the Federal Trade Commission ended an investigation that looked into whether the Clean Truck Partnership violates antitrust laws. The agency was satisfied with commitments from OEMs to ignore the agreement and to never enter into another such agreement again.

For now, the Clean Truck Partnership is in the same state as the emission rules it is trying to enforce: dead. LL