The comment period for proposed EPA emissions regulations starting with model year 2027 ended over the weekend of Sept. 6, 2026.
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. Below are a few of the comments.
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.”
“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.
“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.”
Source: Source: CCJ Comment period for EPA 2027 emissions policy changes ends
PSR Analysis. The truck pre-buy for 2026 is effectively over as the OEM build slots are generally full for the remainder of the year. Due to the transitional period, PSR expects demand to continue to be strong in 2027 as the fleets replace their older trucks with either emission compliant trucks or current trucks with nonconformance penalties. PSR anticipates there will be a modest drop-off in truck demand in 2028. However, due to the transition period a sharp year-over-year decline in sales is not expected.PSR
Chris Fisher is Senior Commercial Vehicle Analyst
