WASHINGTON — In the wake of U.S. Environmental Protection Agency (EPA) administrator Lee Zeldin’s proposal to eliminate deratements, Biden-era NOx emission reduction provisions and addressing a number of other issues impacting trucking, industry insiders are speaking out.
Reactions have been mixed and the NOx emission reduction provision changes and DEF alterations being the most concerning for several organizations.
American Trucking Associations (ATA)
“Since 1970, trucking has reduced heavy-duty emissions by 99%,” ATA said. “That is real progress, and no one should pretend otherwise. But EPA’s 2022 rule demanded another 80% reduction in NOx emissions in just five years, forcing our industry to confront costly, complex technologies that have not been fully proven in real-world conditions.”
According to the ATA, EPA’s existing NOx rule threatened to cause major operational disruptions and significantly increase equipment costs for the trucking industry. ATA has strongly advocated for a reevaluation of the rule and sent a letter to EPA earlier this year requesting modifications. The agency’s proposed revisions incorporate many of ATA’s recommendations.
“ATA has been clear from day one: new environmental standards must be achievable, affordable and reliable,” said Chris Spear, ATA president, CEO. “If a truck cannot perform safely and efficiently on America’s highways, then the freight does not move, shelves do not get stocked and our economy pays the price. Administrator Zeldin and the Trump Administration heard us loud and clear. We appreciate EPA taking our concerns seriously and acting to provide commonsense flexibility for the manufacturers, fleets, and 8.4 million hardworking [people] who keep this country moving. ATA is now reviewing the full details of the proposal released today and looks forward to submitting official comments.”
Owner-Operator Independent Drivers Association (OOIDA)
“Truckers know all too well that poorly implemented emissions regulations result in breakdowns, costly downtime and ultimately set back the goal for cleaner air,” said Jay Grimes, director of federal affairs, OOIDA. “Unfortunately, the NPRM marks a missed opportunity to adequately correct the shortcomings of the 2023 Final Rule. If EPA is unable to amend burdensome NOx emissions standards, we believe there are more productive solutions than drastically cutting extended warranty periods for small-business truckers at the behest of engine manufacturers and large fleets.”
According to Grimes, the rule should ensure that truckers who purchase a new vehicle will not be constantly sidelined because of costly and repeated breakdowns that OOIDA members have historically experienced under new emissions regulations. Given these concerns, sensible warranty programs are critical for encouraging adoption of newer trucks.
“While longer testing timelines and permanent derate flexibility are helpful, they alone will not convince independent truckers that investing in a new vehicle is worth the financial risk,” Grimes said. “We applaud the administration’s notable efforts addressing industry concerns on a number of emissions issues in recent months, but urge EPA to maintain the 450,000 mile warranty coverage for heavy-duty vehicles as MY2027 approaches.”
CALSTART
“EPA’s decision to retain the current stringency of the NOx emissions program for heavy-duty vehicles is a strong testament to the hard work the agency undertook in 2022,” said Michael Berube, CALSTART CEO. “Unfortunately, EPA’s latest proposed changes risk introducing confusion and additional market uncertainty for the heavy-duty truck and engine manufacturers and the fleets that depend on reliable vehicle operation.”
According to Berube, weakening the durability, warranty and inducement provisions that support real-world performance could jeopardize long-term emissions reductions, increase danger to public health and undermine confidence in the technologies needed to deliver cleaner freight today.
“We urge EPA to reconsider these amendments and work collaboratively with key stakeholders to resolve the underlying concerns that led to this proposal,” Berube said. “We look forward to partnering with the agency to shape emissions standards that accelerate technology innovation, deliver reliable and affordable clean freight movement, sustain a thriving domestic automotive and supplier industry and secure fresher air for our communities.”
NATSO and SIGMA
NATSO, representing truck stops and travel centers, and SIGMA: America’s Leading Fuel Marketers, questioned the EPA’s proposal to fundamentally alter the regulatory backdrop for diesel exhaust fluid (DEF) before “the Trump Administration’s previous, thoughtful guidance documents are implemented and the benefits realized.”
“Allowing ample time for existing Guidance to penetrate the market will minimize unnecessary and punitive deratements for diesel vehicles while ensuring that Selective Catalytic Reduction technology remains an essential part of every truck manufacturer’s investment and compliance strategy,” said David Fialkov, head of government affairs for NATSO and SIGMA.
EPA’s proposal would eliminate deratement as a mandatory inducement to satisfy NOx emissions requirements beginning in Model Year 2029.
Customer Confusion
According to NATSO and SIGMA, the proposal will invite consumer confusion and threatens to decrease DEF’s availability and increase its price.
“There is no reason to undermine the common sense measures the Administration has already taken,” the organizations said.
Prior to this proposal, the Trump Administration initiated a series of actions that — when fully implemented — can resolve consumer concerns surrounding diesel exhaust fluid and the operational reliability of DEF-related equipment. NATSO and SIGMA strongly support those efforts. The first Guidance documents issued in 2025 and early 2026 call for large-scale DEF software updates, the use of NOx sensors instead of urea quality sensors, as well as adjustments to the power reduction schedule.
The organizations noted that is precisely what the market needed, but it takes time for the industry to realize the benefits: fewer false warnings and unnecessary repairs and fewer situations where a functioning truck is unnecessarily taken out of service.
Premature Disruption is Counter-Productive
“While the Administration’s impatience is understandable, we believe it is counter-productive to prematurely disrupt that process when allowing it to proceed would negate the need for today’s DEF-related actions,” Fialkov said.
DEF remains an essential product for the reliable operation of commercial trucks regardless of whether EPA mandates that trucks derate. OEMs seeking to comply with EPA’s emissions targets have integrated the use of DEF into the overall fabric of today’s system designs.
“The widespread adoption of DEF technology represents perhaps the most significant environmental success story for liquid fuels in the trucking sector,” Fialkov said. “It is an important demonstration that emissions reductions can be achieved through targeted innovation within the existing liquid-fuels framework.”
NATSO and SIGMA support the benefits that DEF and SCR technology have delivered to emissions reductions and fuel economy.
“NATSO and SIGMA look forward to working with EPA to ensure that any further reform efforts are carefully targeted and evidence-based to avoid diminishing DEF’s availability or increasing its costs for consumers,” the organizations said.
Truck and Engine Manufacturers Association (EMA)
EMA also weighed in on the EPA’s proposed amendments to its 2027 Heavy-Duty On-Highway NOx regulation.
“EMA appreciates EPA’s continued review of elements of its finalized 2027 Heavy-Duty NOx regulation and prioritization of cost contributors,” EMA said. “While EMA is still reviewing the proposed amendments in their entirety, we welcome the Agency’s continued engagement on cost-effective and achievable requirements for manufacturers, truck customers, and equipment operators.”
According to an EMA press release, EMA and its members remain committed to delivering clean, reliable and fuel-efficient commercial vehicle engines that meet national emissions standards while supporting the industries that keep the American economy running. As EPA moves forward, it is critical that the rule be finalized by the end of the year to provide manufacturers with the regulatory certainty necessary for compliance planning, go-to-market strategies, and product availability. That includes ensuring that regulatory mechanisms maintain the proven progress achieved through selective catalytic reduction (SCR) systems, while also reducing unnecessary vehicle or equipment downtime and avoiding operational impacts tied to regulatory inducements.
“EMA looks forward to reviewing the proposal in greater detail and continuing to work constructively with EPA to ensure the final rule supports regulatory certainty and practical implementation for manufacturers and customers,” EMA said.
Dana Guthrie is an award-winning journalist who has been featured in multiple newspapers, books and magazines across the globe. She is currently based in the Atlanta, Georgia, area.
