Street Smarts: Daimler Announces 2027 Cummins Engine Options

The Cummins B6.7 Octane brings a purpose-built gasoline will be available in the medium-duty Freightliner M2 106. (Photo: Cummins)

There has been a lot of smoke and mirrors surrounding 2027 heavy-duty engine offerings. The state of play regarding both California Air Resources Board (CARB) and U.S. Environmental Protection Agency (EPA) regulations has been uncertain ever since Donald Trump returned to the White House in 2025. But things are slowly coming into focus as we draw nearer to 2027.

The latest clarity comes from Daimler Truck North America (DTNA). The OEM announced it is expanding its 2027 powertrain portfolio with the addition of several new Cummins engine options. These new options will, of course, be offered alongside Detroit’s next-generation diesel platform across Freightliner and Western Star models.

Daimler said the move broadens the range of engines available to fleets as the industry prepares for the EPA’s 2027 emissions regulations.

New Fuel Options

Interestingly, Daimler’s expanded lineup includes Cummins’ new B6.7 Octane gasoline engine. That’s in addition to the clean-sheet X10 platform and a redesigned X15.

“Cummins is a critical partner for DTNA, and integrating their engines ensures our portfolio covers the full spectrum of applications for our customers,” said Joanna Buttler, general manager of Product Strategy and Market Development for DTNA. “Their next generation of engines strengthen the range of powertrain solutions available across Freightliner and Western Star, and support customers as they prepare for upcoming emissions requirements and long-term operational needs.”

Buttler said the Cummins B6.7 Octane brings a purpose-built gasoline option to the medium-duty segment and will be available in the Freightliner M2 106. Designed specifically for commercial applications, the engine produces up to 300 hp and 660 lb.-ft. of torque while running on widely available 87-octane gasoline. Cummins said the engine aims to deliver diesel-like performance while offering simplicity and affordability associated with gasoline powertrains.

Daimler said the redesigned Cummins X15 will continue as a cornerstone engine for heavy-duty applications. (Photo: Cummins)

All Cummins engines offered by Daimler next year are built on Cummins’ HELM platform architecture. “HELM” is an acronym that stands for “Higher-Efficiency, Lower-Emissions, Multiple Fuels.”

The HELM engines use a common base architecture that supports multiple combustion systems. They can be easily configured to run diesel, gasoline, natural gas or even liquid hydrogen as fuel.

The HELM design also allows the B6.7 Octane to deliver strong torque response for demanding duty cycles, including operations in hilly terrain and cold environments, according to Cummins.

The B6.7 engine also features a simplified emissions system using a three-way catalyst that eliminates diesel exhaust fluid, active regenerations and diesel aftertreatment hardware.

Cummins said fuel efficiency can be up to 10% better than comparable gasoline engines, while oil service intervals can extend to 15,000 miles.

“The B6.7 Octane provides fleets a commercial-grade gasoline solution built for tough duty cycles without increasing maintenance demands,” said Jim Nebergall, executive director of Product and Market Strategy at Cummins. “By combining diesel-like durability with gasoline simplicity, the B6.7 Octane offers customers dependable performance in a footprint they already trust.”

The order book for the B6.7 engine is currently open, with production slated to begin in the third quarter of 2026.

Options for targeted MD and HD applications

Daimler said its expanded 2027 lineup will also include the new Cummins X10 and a redesigned X15 engine for 2027 model-year trucks.

The X10 is a clean-sheet design intended to replace both the Cummins L9 and X12 engines. It delivers up to 380 hp for medium-duty applications and up to 450 hp in heavy-duty configurations.

The engine incorporates a new 48-volt electrical system designed to quickly heat emissions control components during cold starts, helping reduce emissions and support compliance with EPA 2027 standards.

Daimler said the redesigned X15 will continue as a cornerstone engine for heavy-duty applications. Cummins said it has updated the X15 to meet the upcoming emissions requirements while maintaining the durability and performance that have made it widely used in long-haul operations.

The Detroit Gen 6 engines incorporate design updates aimed at improving efficiency while meeting 2027 emissions requirements. (Photo: Daimler Truck North America)

In addition to the new platforms, several existing Cummins engines will continue in the lineup, including the B6.7 diesel, the L9N natural gas engine and the X15N natural gas engine for heavy-duty and long-haul applications.

Together, Daimler and Cummins said, these new engine options provide fleets with multiple fuel and powertrain pathways depending on operational requirements, emissions strategies and long-term business planning.

Detroit Engines anchor DTNA diesel offerings

Alongside the Cummins offerings, DTNA will, of course, offer its new Detroit Gen 6 diesel engine platform. Launched earlier this year, the Detroit Gen 6 engine platform includes the DD13, DD15 and DD16.

Daimler said Gen 6 engines build on a proven platform with more than 1.2 million units already in service. The new engines also incorporate a series of design updates aimed at improving efficiency while meeting the more stringent 2027 emissions requirements.

Jack Roberts is a Tuscaloosa, Ala.-based independent journalist and licensed commercial driver with more than 20 years’ experience covering the North American and global trucking industries.

Key changes include a redesigned fuel system that removes amplified injection while delivering stronger and more consistent fuel flow. An asymmetric intake port increases swirl and improves fuel and air mixing, while Miller timing on the camshaft reduces compression work and improves overall efficiency.

To meet stricter nitrogen oxide limits under the EPA’s 2027 rules, the Gen 6 engines will incorporate a pre-selective catalytic reduction system placed upstream of the main aftertreatment system. Combined with a thermal control valve, the design allows the aftertreatment system to reach operating temperature more quickly, reducing the need for parked regenerations.

DTNA said the new aftertreatment system preserves existing chassis space and does not affect back-of-cab packaging, an important consideration for vocational applications and truck equipment manufacturers.

Production of the Detroit Gen 6 DD13 and DD15 engines is scheduled to begin in January 2027, followed by the DD16 in January 2028.