The EPA's comment period for proposed 2027 NOx emissions regulations has closed after receiving over 100 industry comments.
- The EPA received more than 100 comments on proposed emissions regulations for model year 2027 heavy-duty trucks and engines.
- Proposed amendments include modifications to useful life periods, emission-related warranty periods, and the introduction of nonconformance penalties (NCPs) for engine manufacturers beginning in 2027.
- Industry stakeholders are concerned about vehicle costs increasing $15,000 to $20,000+ due to new NOx standards requiring reduction from 200 mg/hp-hr to 35 mg/hp-hr.
The comment period for proposed EPA emissions regulations starting with model year 2027 ended over the weekend.
The regulatory amendments would include changes to the useful life periods and emission-related warranty periods. There are also amendments to the January 2023 provisions and from earlier rules. The agency also plans to make nonconformance penalties (NCPs) available to engine manufacturers beginning in 2027 and to amend inducement provisions.
"Americans depend on reliable trucks to move essential goods across the country," EPA Administrator Lee Zeldin says. "If finalized, these changes will help manufacturers keep improving their vehicles without being forced to rush products to market before they're ready. Combined with the Trump EPA's first proposed deregulatory action to address ongoing DEF problems, this will ease real burdens for operators.
More than 100 comments were submitted. Here’s what the industry had to say.
National Association of Small Trucking Companies (NASTC)
“Our special concern is that EPA delivers a far better set of improvements over the status quo for new heavy-duty vehicles that will remain out of reach for small carriers while OEMs drag their feet and slow-walk taking measures to make life better for the thousands of commercial drivers in vehicles already in use. That scenario would be an unfair, regrettable outcome.
“Should this outcome develop, the rule should provide a contingency requirement that takes effect one year after directing OEMs to disable SCR and DEF systems on any and every vehicle for which the vehicle owner requests disablement, which should be completed within 15 days of the request. OEMs that refuse to comply with requests in a timely manner should be held liable to pay an appropriate fee that is equally divided between the agency, compensating for the resulting NOx emissions resulting from equipment disablement for the remaining use of the vehicle, and the vehicle owner, compensating him or her for being forced to remain under the derate regime.”
Truck and Engine Manufacturers Association (EMA)
“The modifications to the emissions warranty and useful life provisions will make the 2023 Final Rule more implementable for manufacturers and more cost-effective for trucking fleets and other heavy-duty diesel vehicle and equipment operators. More specifically, the proposal to retain the current emission warranty periods will allow up-front reductions in product costs. The proposed deferral of the longer useful life periods similarly will enable more effective and robust technology development and lower costs. And the proposed clarifications and corrections to many of the other compliance provisions will provide manufacturers with enhanced regulatory clarity.”
Prime Inc. (No. 15 on the CCJ Top 250)
“(W)e support extending the availability of EPA 2024 emissions-compliant products through 2027 and urge EPA to maintain this extended timeline.
“… Prime has experienced the consequences of premature technology adoption, including unplanned downtime, parts shortages, increased maintenance requirements and limited service capacity. Before widespread adoption within our fleet, we need sufficient EPA 2027 field experience to understand long-term durability, failure rates, maintenance costs, parts availability and service readiness.”
Hunter Truck
“I am concerned that imposing thousands of dollars in nonconformance penalties on otherwise proven, reliable engines is not a practical solution.
“These penalties do not disappear at the manufacturer level. Costs imposed on an engine manufacturer become costs to the truck manufacturer, dealer, fleet owner, independent trucker, freight customer and ultimately the American consumer. At a time when trucking companies are already dealing with high equipment costs, insurance expenses, interest rates, maintenance costs, labor pressures and uncertain freight markets, adding thousands of dollars to the cost of an engine creates another financial burden on the very industry responsible for moving nearly every product Americans purchase.
“If EPA believes that continued production of engines meeting the previous emissions standards is appropriate during the transition to the 2027 standards, it raises an important question: Why should the purchaser of that engine be financially penalized for buying a product that EPA is allowing to remain in commerce?”
Volvo Group
“Since EPA finalized the 2023 Heavy-Duty Low-NOx Rule, the Volvo Group has made substantial investments in the development of a new engine family, advanced vehicle platforms and aftertreatment technologies to comply with the highly stringent NOx standards that take effect on Jan. 1, 2027. …
“The proposed Low-NOx Amendments would provide greater flexibility within the framework of the 2023 Final Rule, help reduce vehicle acquisition costs, and allow manufacturers to ramp up production in a controlled manner while supporting increased customer confidence as they transition their operations to the new technologies.
“… We agree with EPA’s decision to maintain the 35 mg/bhp-hr NOx standard in the rule. The Volvo Group remains committed to meeting customer demand by supplying compliant engines and vehicles supporting a stable and successful market transition.”
American Trucking Associations
“We encourage EPA to expeditiously finalize these flexibilities and to monitor the ongoing implementation. Challenges remain in the rollout of these near-zero NOx emissions standards and it is imperative that new trucks in 2027 and beyond are affordable, reliable and allow the trucking industry to continue to deliver for our economy.
“Our industry has reduced NOx emissions from today’s heavy-duty trucks by 98% since 1985 and the 2027 standards represent an additional 80% reduction. By providing commonsense flexibility, EPA is supporting the manufacturers, fleets and 8.4 million hardworking men and women who keep our country moving. At the same time, the proposed rule retains 90% of the projected NOx emissions reductions that were envisioned under the 2023 standards.”
Inland Kenworth
“I understand that the EPA is working to keep engine emissions levels under control. The NCP does matter. DEF costs and ROI calculations of the first owner (generally 2-4 years), not the full 10-year vehicle life, need to be adjusted to reflect accurate (lower) DEF consumption in newer engines.”
International Motors
“International generally supports EPA’s proposed regulatory amendments to the heavy-duty highway engine and vehicle programs. The Proposed Rule’s targeted revisions to emission-related warranty periods, regulatory useful life, production volume allowances and SCR inducement provisions, among its other proposed changes and additions, represent a balanced approach that will reduce compliance costs while maintaining the core emission reduction objectives of the 2023 Final Rule that take effect in MY 2027. …
“Notwithstanding International’s overall support of the Proposed Rule, International has several specific comments and recommendations aimed at maintaining the competitive landscape and ensuring the level playing field that currently exists remains. Over the last several decades, International has taken an industry lead in developing sustainable transportation solutions that resulted in dramatic reductions in NOx and other emissions. In reliance on the 2023 Final Rule, International invested considerable time and resources in its new heavy-duty powertrain and vehicle technologies to meet federal EPA standards, achieving best-in-class status through, among other things, superior fuel economy. As discussed herein, some of EPA’s suggested ‘alternatives’ would unfairly skew the competitive playing field. These suggested alternatives are unnecessary from a cost and technological perspective.”
Murphy-Hoffman Company (MHC)
“New commercial purchasers typically evaluate equipment investments based on projected cash flow, maintenance exposure, residual value expectations, financing cycles and replacement budgets. As a result, future operating expenses occurring many years after the original transaction generally do not influence the purchasing decision that NCPs are intended to model. …
“[P]rojecting DEF costs over the entire useful life of a vehicle attributes future expenses to the new truck purchasing decision even though those costs are frequently borne by different owners under different operating conditions. …
“For these reasons, MHC is in favor of limiting DEF cost calculations to no more than four years and preferably to the period that reflects the typical ownership horizon of the initial purchaser of three years.”
Kenworth Sales Company
“[W]e are informing the EPA of our support of reducing the DEF costs included in the calculation of the NCP to no more than four years of an engine’s life. … Reducing the DEF cost horizon to four years aligns with the actual holding period of the initial owner who is directly affected by the NCP.
“The high NCPs calculated using 10 years instead of four will discourage customers from purchasing engines manufactured in the United States by Paccar despite the heavy investment required to reduce NOx emissions from 200 mg/hp-hr to 35 mg/hp-hr.”
GTG Peterbilt
“I would ask you to consider allowing nonconformance penalties for 2027 and beyond. While I believe our manufacturer as a strong path to achieve these regulations, additional time to refine the technology will allow us to provide a better product to our customers and do so with decreased impact to their businesses. As we understand it today, moving forward with the new technology would add roughly $15,000 to the cost of a vehicle. … This price increase would be directly passed on to the customer, further stressing an already delicate economic situation. Allowing a nonconformance penalty would allow us to reduce the impact of the price change.”
Werner Enterprises (No. 14 on the CCJ Top 250)
“The Proposed Rule demonstrates progress toward balancing environmental goals with real-world fleet reliability and efficiency. However, because original regulatory modeling significantly understated the total cumulative cost on carriers — pushing actual new truck prices $15,000 to $20,000+ higher — unadjusted NCP formulas risk compounding financial strain on carriers. Left unadjusted, these excessive costs will force carriers to delay fleet modernization, keeping older, higher-emitting trucks on the road longer and directly undermining total emissions reductions. Werner Enterprises respectfully urges the EPA to finalize the proposed rule with our recommended downward adjustments to NCP formulas, realistic 55 mph derate caps, winter freeze protections, and permanent baseline useful life standards. Properly structuring these provisions will keep modern equipment affordable, accelerate the retirement of older fleets and deliver cleaner air faster.”
