CALSTART Media Contact: Jennifer Smith, CALSTART (626) 744-5645, jsmith@calstart.org  

WASHINGTON, D.C.— Today, the U.S. Environmental Protection Agency (EPA) proposed revisions to nitrogen oxides (NOx) emissions standards for heavy-duty vehicles, model years 2027 and later. While the proposal preserves the core tailpipe stringency of the landmark standards, it would amend key implementation provisions, including warranty, useful life requirements, and inducement provisions that ensure emissions control systems perform reliably over a truck’s operational lifetime.

As a result, the proposed changes could create uncertainty for truck and engine manufacturers already working to deliver reliable, compliant vehicles in a globally competitive market, while also risking increased pollution in communities near freight corridors.

In response to the proposal revisions, CALSTART’s CEO, Michael Berube, stated:

“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. 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. 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. 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.”

Background

EPA finalized new heavy-duty NOx emissions standards in December 2022 for model years 2027 and later vehicles. The rule included lower NOx emissions limits, longer useful life requirements, longer emissions warranty periods, and updated requirements related to selective catalytic reduction systems and diesel exhaust fluid.

Selective catalytic reduction systems use diesel exhaust fluid to reduce NOx emissions from diesel engines. These systems are central to meeting the 2027 heavy-duty NOx standards.

Useful life requirements define the period over which engines and vehicles are expected to meet emissions standards. Emissions warranty requirements establish the period during which manufacturers are responsible for certain emissions-related repairs. Operator inducement provisions are designed to ensure that emissions-control systems remain properly functioning during vehicle operation.

EPA’s proposal would revise certain implementation provisions of the 2027 heavy-duty NOx program, including provisions related to useful life, warranty, and inducements.

About CALSTART

CALSTART is a global nonprofit that brings together industry, government, and communities to advance and accelerate affordable clean transportation solutions accessible to all. Our work is critical to delivering cleaner air, curbing climate change, and creating economic opportunity. Learn more at calstart.org.