Detroit, Daimler Truck North America’s powertrain brand and leading manufacturer of heavy-duty truck engines and commercial vehicle components, recently announced its new Gen 6 heavy-duty engine portfolio, comprised of the DD13, DD15 and DD16. The next evolution of its popular engines is fully compliant with the EPA’s 2027 standard and will be available for all heavy-duty Freightliner and Western Star trucks. 

“Freightliner and Western Star customers depend on Detroit to operate reliably, efficiently and powerfully, and we’re honored by the trust placed in both the Detroit brand and the DD13, DD15 and DD16 engines to help navigate past transitions as well as this next one,” said David Carson, senior vice president of sales and marketing at Daimler Truck North America. “With our Gen 6 engines, we have a successor that builds on years of proven performance to be prepared for ’27 and beyond.”

All Detroit engines are manufactured in the US at the Redford, Michigan campus. The Detroit Gen 6 DD13 and DD15 engines will be available beginning in January 2027, with Gen 6 DD16 production following in January 2028.

At their core, the Detroit Gen 6 engines refine the previous generation’s design, providing confidence that the durability and reliability that Detroit is known for continue, said a statement from th company. As part of their updates, the engines deliver enhanced efficiency designed to help offset the impacts from emissions-related changes. A redesigned and simplified fuel system removes the need for amplified injection and supplies higher, stronger and more consistent fuel flow.

Similarly, the addition of an asymmetric intake port increases swirl, and, combined with new fuel injectors, improves fuel and air mixing for a more complete combustion. The use of Miller timing on the camshaft reduces the work of compression, increases the compression ratio and contributes to overall engine efficiency.

To meet compliance with stringent NOx requirements included in EPA’s 2027 standards, Detroit Gen 6 engines use a pre-Selective Catalytic Reduction (pre-SCR) system – containing the same robust, familiar elements of the main aftertreatment system (ATS) – positioned upstream of the primary ATS. This proven and known technology, combined with a thermal control valve, helps the ATS to reach operating temperature more quickly, reducing the need for parked regens.

The ATS design preserves existing chassis space with no impact to back-of-cab packaging, a key advantage for vocational customers and truck equipment manufacturers. A new wastegate actuator also improves braking performance and gradeability with greater power for high altitude conditions. New engine ratings of up to 1,900 lb.-ft of torque enable greater downspeeding capabilities for the right combination of power and efficiency.