Detroit introduces its 2027 heavy-duty Gen 6 engines
Detroit, Daimler Truck North America’s powertrain brand and leading manufacturer of heavy-duty truck engines and commercial vehicle components, announced on February 19th 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.”
Dependable and familiar technology to improve efficiency and meet stringent standards
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. 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.
20 years of a proven platform
First announced in 2007, Detroit’s DD engine series, also known as the Heavy-Duty Engine Platform (HDEP), was introduced as a clean sheet design to help fleets navigate a rapidly changing regulatory landscape without compromising reliability, efficiency or power. Following its introduction in 2007, each successive generation – delivered in 2010 (Gen 2), 2013 (Gen 3), 2016 (Gen 4) and 2021 (Gen 5) – met increasingly stringent emissions standards while continuing to deliver the performance and uptime customers expect from Detroit. This continuous improvement helped to solidify the DD engine series as a leading choice across the industry. Today, there are 1.2 million heavy-duty engines operating in on-highway and vocational applications, delivering reliably for fleets across North America and other global markets.
More than an engine
As the leading powertrain brand, Detroit integrates advanced engines with Detroit Assurance safety systems to help protect drivers and strengthen fleet confidence on the road. Detroit Assurance is a core part of Detroit’s engineering approach, applying radar- and camera-based systems that support safer decision-making through features such as Active Break Assist, Adaptive Cruise Control and Side Guard Assist. Detroit Connect complements these systems by providing real-time data, predictive analytics and proactive support that give fleets greater visibility into performance and maintenance needs. Together, they form an integrated, safety-driven powertrain ecosystem designed to improve reliability, reduce downtime and help fleets operate efficiently throughout the vehicle lifecycle.
Nearly a century of trusted engines
All Detroit engines are manufactured in the US at the Redford, Michigan campus. Home to North American engine and component research and development for Daimler Truck North America, as well as engine, transmission and axle production, the facility employs more than 2,000 people. Since its founding in 1938, Detroit has long been a stalwart of automotive manufacturing in the area and most recently received an investment of $285 million – supported by incentives from the Michigan Economic Development Corp. and the Michigan Strategic Fund – to enable, in part, the manufacture of Gen 6 engines.
The Detroit Gen 6 DD13 and DD15 engines will be available beginning in January 2027, with Gen 6 DD16 production following in January 2028.
