Cummins’ New X10 Engine Will Emit 75% Less NOx

Cummins Inc. announced on Feb. 13 the launch of the next engine in its “fuel-agnostic” series, the X10, in North America in 2026. This engine, named as part of the X engine family, will replace both the L9 and the X12 to serve medium- and heavy-duty applications.

The X10 will be compliant with U.S. EPA’s 2027 regulations a full year early, according to Cummins. It will emit 75% less nitrogen oxide (NOx) emissions than current engines.

The diesel version will be first available, with other versions for gaseous fuels introduced later. This 10-liter X10 slots into Cummins’ product portfolio in between the B6.7 and X15 and will serve vocational, transit, pickup and delivery, and regional haul customers.

“We are committed to advancing diesel technology while our markets and our customers need it to run their businesses. The new X10 has been designed drawing on our decades of experience as a leader in the medium- and heavy-duty space,” said José Samperio, executive director, North America On-Highway at Cummins Inc. “We have applied those learnings to ensure the product will perform for our customers and the important jobs they need to do every time.”

Though the engine will first be available in Europe and North America, it will be introduced in other regions over time and will be made for off-highway markets as well, according to Cummins.

The X10 architecture uses a belt-driven 48-volt alternator and aftertreatment heater solution optimized for the new emission standards and will be scalable to other advanced combustion technologies, according to Cummins. For further reductions in carbon emissions, customers can choose to use B20 or renewable diesel.

Extended Maintenance Intervals

The engine can be paired with a variety of transmissions depending on the application, including the Eaton Cummins Endurant. The X10 is expected to offer extended maintenance intervals to help reduce visits to the shop. The engine is equipped with Acumen, which provides digital connectivity and direct access to a range of applications and capabilities including over-the-air calibration and predictive service recommendations.

The engine is built on Cummins’ fuel agnostic platform, which feature a series of engine versions that are derived from a common base engine with some parts commonality, according to Cummins.

Below the head gasket of each engine will largely have similar components and above the head gasket will have different components for different fuel types. Each engine version will operate using a different, single fuel.

Cummins portfolio of products for 2026 will also include the new 15-liter natural gas engine, the X15N. Additionally, the B6.7 will be offered in diesel, natural gas, gasoline, and propane.