[Stay on top of transportation news: Get TTNews in your inbox.]
ATA anticipates NOx proposed rulemaking from EPA this week
Office of Management and Budget completes NPRM review
Key Takeaways:
- EPA is expected to release a draft NOx emissions proposal after OMB completed its review before the Independence Day holiday.
- ATA expects the proposal to add flexibility, including changes to warranty requirements and compliance credit availability.
- Uncertainty over regulatory details has led carriers to delay truck purchases despite available compliant engines.
The Environmental Protection Agency is expected to release a draft of its long-awaited notice of proposed rulemaking (NPRM) on changes to nitrogen oxide tailpipe emissions this week, according to American Trucking Associations.
The Office of Management and Budget completed its review of EPA’s proposal to expand flexibility for truck manufacturers before the Independence Day holiday, Henry Hanscom, ATA’s chief advocacy and public affairs officer, told the trade group’s members in a July 6 letter.
An NPRM is a formal document issued by a federal agency that announces the intent to change, add or remove regulations. It outlines the proposal and invites public comment. OMB reviews agency regulations and manages the federal budget.
EPA is set to leave in place a Biden-era requirement that NOx emissions for heavy-duty trucks fall to 35 milligrams per horsepower-hour from 200 mg/hp-hr.
But the trucking industry is still waiting for clarity on key details — including warranty requirements — that when regulations are being introduced typically would have been released much earlier.
Image
Hanscom
ATA expects EPA to rescind an extended warranty mandate and restore EPA’s previous warranty and useful-life requirements; expand the availability and flexibility of compliance credits; and allow the temporary use of nonconformance penalties for manufacturers.
EPA did not respond to a request for comment on when the NPRM would be released.
Some truck makers told carriers at the 2026 Advanced Clean Transportation Expo in May that potential price hikes could be cut in half if the five-year, 100,000-mile warranty terms remain unchanged for engine emissions systems.
Those potential price hikes have seen carriers adopt a wait-and-see approach to tractor purchases even though truck makers already have their EPA 2027-compliant engines ready.
Image
Hillman
David Hillman, International Motors vice president of integrated technology sales, told ACT attendees: “Not a week goes by that me and my team don’t get asked, ‘What’s the pricing on this?’ … We don’t know the pricing yet today. But I don’t begrudge you if you want to ask.
“What we don’t want to do is [establish a] price given the regulations on the books right now, and then have an NPRM come out that dramatically changes that and then everyone has to reshuffle.”
Traton division International unveiled plans in January for an EPA 2027-compliant S13 engine. The S13 integrated powertrain was initially launched in August 2022.
Hanscom noted in the letter that ATA supports emissions reduction and believes these flexibilities — combined with a continued commitment to using diesel exhaust fluid — will allow trucking to build on decades of environmental progress.
EPA Administrator Lee Zeldin announced in March 2025 that the 2022 Heavy-Duty Nitrogen Oxides (NOx) rule would be re-evaluated.
