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DTNA to open Detroit Gen 6 engines order book Sept. 1
Freightliner, Western Star buyers to receive just EPA 2027 engines
DTNA, unlike some of its peers, will discontinue engines that meet current NOx regulations but not the stricter standards taking effect Jan. 1. (Daimler Truck North America)
Key Takeaways:
- Daimler Truck North America will open orders Sept. 1 for Gen 6 DD13 and DD15 engines for Freightliner and Western Star trucks.
- DTNA will discontinue current-standard engines, diverging from Cummins and Paccar despite EPA flexibility on implementing stricter 2027 nitrogen oxide limits.
- Gen 6 DD13 and DD15 engines become available in January 2027, followed by DD16 production in January 2028.
Daimler Truck North America is set to open the order book for the latest Detroit DD13 and DD15 engines on Sept. 1 for Freightliner and Western Star trucks, the company said Aug. 27.
The Generation 6 engines meet Environmental Protection Agency 2027 nitrogen oxide emissions rules scheduled to become effective Jan. 1.
DTNA, unlike some of its peers, will discontinue engines that meet current NOx regulations but not the stricter standards taking effect Jan. 1.
While NOx regulations are set to tighten in 2027, the EPA on July 9 offered engine manufacturers wiggle room on implementation, noncompliance penalties and NOx credits.
“Customers don’t want to choose between proven performance and future-ready technology. With the Detroit Gen 6 engine platform, they don’t have to,” DTNA Senior Vice President of Sales and Marketing David Carson said Aug. 27. “We’ve built on the foundation customers already know and trust while introducing targeted improvements that make the transition to EPA 2027 straightforward.”
DTNA launched its EPA 2027-compliant engines in February, with the Gen 6 portfolio comprising 13-liter DD13, 15-liter DD15 and 16-liter DD16 engines for heavy-duty Freightliner and Western Star trucks.
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 EPA regulations, a conscious decision that Daimler Truck CEO Karin Radstrom said would reduce the price of the engines.
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Radstrom. (Carina Johansen/Bloomberg)
“We don’t need the 48-volt system, which means the incremental cost increase is not that high,” the executive said during the second-quarter 2026 earnings call for DTNA’s parent company.
Cost has been a key concern about the introduction of the new engines.
About 75% of Gen 6’s core components carry over from the previous generation of engines, DTNA said.
Gen 6 engines incorporate a redesigned fuel system for more consistent fuel flow, and Detroit added a preselective catalytic reduction system upstream of the primary aftertreatment system to help the emissions system meet the new regulatory requirements.
Detroit’s current heavy-duty engine platform debuted in 2007, and more than 1.2 million engines have been sold for on-highway and vocational applications. Successive generations were launched in 2010 (Gen 2), 2013 (Gen 3), 2016 (Gen 4) and 2021 (Gen 5).
Answering a question during the Q2 earnings call, Daimler Truck Chief Financial Officer Eva Scherer confirmed to investors that DTNA would only sell 2027 EPA-compliant engines.
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Jefferies analyst Michael Aspinall sought confirmation from Scherer and 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.”
Executives at engine manufacturer Cummins and truck maker Paccar — the parent company of Kenworth and Peterbilt — earlier in the most recent earnings season said the companies 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 EPA 2027-compliant engines for its tractors and trucks, Traton Group CEO Christian Levin told analysts during the company’s own earnings call July 23.
After years of work, engine and truck makers faced a tough decision on how to address customers’ concerns when the EPA promised in March 2025 to reassess the regulations.
In the end, EPA kept a Biden-era requirement that NOx emissions from heavy-duty trucks fall to 35 milligrams per horsepower-hour from 200 mg/hp-hr.
