New engine will meet 2027 emissions standards and run on multiple fuels

Cummins Inc. will retire its L9 and X12 legacy engines, replacing them with a new X10 engine capable of powering medium- and heavy-duty trucks on a variety of fuels.

The move is consistent with Cummins’ plan to offer its X15 engine family powered by natural gas, hydrogen, propane and possibly other combustible fuels as an interim solution along with zero-emission battery- and fuel cell-electric powertrains.

The fuel-agnostic engine platforms feature a series of engine versions derived from a common base engine. Below the head gasket, each engine has similar components. Components above the head gasket contain components for different fuel types. Each engine runs on one fuel.

New Cummins engine slots between medium- and heavy-duty applications

The 10-liter displacement product slots between the B6.7 for vocational, transit, pickup and delivery and regional haul customers and the X15 focused on long-haul trucking. The X10 will start as a diesel engine and add other gaseous fuels, including B20 and renewable diesel.

Cummins plans to offer the X15N powered by natural gas in 2024 and the X15H with hydrogen combustion in 2027.

“We are committed to advancing diesel technology while our markets and our customers need it to run their businesses,” José Samperio, Cummins executive director of the North America On-Highway business, said in a news release.

The new Cummins X10 engine debuts in 2026 with a 75% reduction in nitrogen oxide emissions. (Photo: Cummins)

New engine emits 75% fewer NOx emissions

The new X10 diesel will emit 75% less nitrogen oxide emissions than current engines and comply with the U.S. Environmental Protection Agency 2027 regulations. The X10 architecture uses a belt-driven, high-output 48-volt alternator. An aftertreatment heater is scalable to other advanced combustion technologies such as cylinder deactivation.

Cummins acquired Jacobs Automotive Systems, a maker of cylinder deactivation technology, in 2022. It also partnered with startup Tula Technology to test diesel Dynamic Skip Fire technology that reduced NOx emissions by 74% in the X15 engine.

“It will be scalable to other advanced combustion technologies, but it’s too early to say which may be implemented,” spokesperson Katie Zarich told FreightWaves.

The engine can be paired with several transmissions, including the Eaton Cummins Endurant for better drivability and efficiency from idle to full power. The X10 has longer maintenance intervals, reducing visits to the shop. Over-the-air calibration, predictive service recommendations and other features come through Cummins’ Acumen digital connectivity.

The new engine will first be available in Europe and North America. Other regions will get it later and an off-highway version is part of the long-term plan.