Cummins will launch the next engine in the fuel-agnostic series, the X10, in North America in 2026. This engine, named as part of the X engine family, is positioned to replace both the L9 and the X12 with the versatility to serve both medium- and heavy-duty applications.
It will be compliant with US EPA’s 2027 regulations a full year early. The diesel version will be first available, with other versions for gaseous fuels introduced later. This 10-liter displacement product slots into Cummins’ product portfolio complemented by 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.—José Samperio, Executive Director – North America On-Highway at Cummins Inc.
The X10 will offer a range of ratings from 320hp to 450hp (torque 1000 - 1650 lb-ft / 1356 - 2237 N·m) and will play an important role serving customer needs. Cummins maintains that diesel will remain a critical technology for the commercial vehicle market for years to come, and the company will continue to support it. 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.
The new X10 diesel will emit 75% less NOx emissions than required at launch in 2026. It will be compliant to the US EPA’s 2027 regulations while providing a step change in fuel economy improvement.
The X10 architecture uses a belt-driven, high output 48-volt alternator and aftertreatment heater solution optimized for increasingly stringent emission standards, and will be scalable to other advanced combustion technologies. For further reductions in carbon emissions, customers may choose to use B20 or renewable diesel.
The engine can be paired with a variety of transmissions depending on the application including the Eaton Cummins Endurant to enable additional drivability benefits and efficiency gains.
The X10 aims to be exceptionally efficient from idle to full power, which is critical for transient applications. Its extended maintenance intervals can help reduce visits to the shop.
The engine is equipped with Acumen, which provides digital connectivity and direct, immediate access to a range of applications and capabilities. These capabilities provide value throughout the lifecycle of the engine and include over-the-air calibration, predictive service recommendations and additional features that help fleets keep their trucks and equipment on the road.
Fuel Agnostic Platform. The engine is built on Cummins’ fuel agnostic platform. These new fuel-agnostic engine platforms feature a series of engine versions that are derived from a common base engine, which means they have some parts commonality. 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 is offering a full portfolio of products in 2026 to cover the medium-duty and heavy-duty customer needs, including the new 15-liter natural gas engine, the X15N. Additionally, the B6.7 will be offered in diesel, natural gas, gasoline and propane.