DTNA commits to just EPA 2027 engines when NOx rules launch

A technician works on a diesel engine at DTNA's manufacturing plant in Cleveland, N.C., in 2025. (Daimler Truck North America)

Daimler Truck North America, unlike some of its peers, does not plan to continue offering engines that comply with current nitrogen oxide regulations but not the tighter tailpipe-emissions standards that take effect Jan. 1, 2027, the top executives at its parent company said Aug. 7.

NOx regulations are set to tighten in 2027, but the Environmental Protection Agency on July 9 offered engine manufacturers wiggle room on implementation, noncompliance penalties and NOx credits.

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Scherer 

Answering a question during Daimler Truck’s second-quarter 2026 earnings call, Chief Financial Officer Eva Scherer confirmed to investors and analysts that DTNA would only sell 2027 EPA-compliant engines.

Jefferies analyst Michael Aspinall sought confirmation from Scherer and CEO Karin Radstrom after the latter told analysts: “We will change over our production to the new engines. As Eva already stated, we have what we believe to be extremely robust engines, a very good technical solution … we are definitely confident that these engines will perform with our customers, and that’s why we will not run parallel programs going into ’27.”

In contrast, executives at engine manufacturer Cummins and truck maker Paccar — the parent company of Kenworth and Peterbilt — said they will continue to build and offer 2026 engines to customers when the new regulatory regime debuts.

International Motors is also mulling staggering the introduction of 2027 EPA-compliant engines for its tractors and trucks, Traton Group CEO Christian Levin told analysts during the company’s own earnings call July 23.

EPA’s draft revision of its nitrogen oxide emissions rule includes rolling back warranty requirements for new heavy-duty trucks alongside the softer compliance standards.

The draft was unveiled by Administrator Lee Zeldin at the America 250 Great American State Fair. DTNA CEO John O’Leary, Cummins CEO Jennifer Rumsey and Paccar CEO Preston Feight were all on the dais with Zeldin at the unveiling.

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From left: ATA President Chris Spear, Rumsey, Feight and O'Leary pose for a photo. (American Trucking Associations)

However, 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, as expected.

DTNA launched its EPA 2027-compliant engines in February, with the Detroit Gen 6 portfolio comprising 13-liter DD13, 15-liter DD15 and 16-liter DD16 engines for heavy-duty Freightliner and Western Star trucks.

To meet the tougher NOx standards, the engines use a pre-selective catalytic reduction system positioned upstream of the primary aftertreatment system.

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The Detroit Gen 6 DD15 engine. (Detroit via broadhead)

At the unveiling, DTNA said Gen 6 DD13 and DD15 engines would be available starting in January 2027, with Gen 6 DD16 production starting in January 2028.

Unlike some of its peers, Detroit did not add 48-volt electrically heated aftertreatment components to meet the emissions regulations, which Radstrom said was a conscious decision and would cut the price of DTNA’s 2027 EPA-compliant engines.

“We don’t need the 48-volt system, which means the incremental cost increase is not that high,” said the executive.

Cost has been a key factor in concerns about the introduction of the new engines.

The Trump EPA acknowledged this with the fine print of its draft rulemaking, insisting warranties for heavy-duty truck emissions-mitigation equipment be kept to 100,000 miles or five years rather than 450,000 miles or 10 years under the existing rule.

EPA said it expects carriers to see up to $6,000 per vehicle in emissions-related warranty savings.

Some truck makers told customers in May that potential price hikes — estimated at $20,000 — could be cut in half if the 100,000-mile or five-year warranty terms were in place.