Q&A: Cummins On-Highway Execs on the Future of Truck Engines
Cummins Unveils X10 Fuel-Agnostic Engine
The Cummins X10 engine will debut as a diesel first, with versions that can run on other gaseous fuels being released in the future.

The Cummins X10 engine is positioned to replace both the L9 and X12 engines in both medium- and heavy-duty applications.
Photo: Cummins
At a press event in Columbus, Indiana, in the summer of 2022, Cummins made it clear that all options are on the table as it presses forward helping fleets in North America and around the globe transition to cleaner transportation options. Now, the global engine and automotive technology supplier has announced another major stepping-stone on that journey with the release of its new X10 fuel-agnostic engine.
According to Cummins engineers, the X10 engine is positioned to replace both the L9 and X12 engines in both medium- and heavy-duty applications. It will also be compliant with U.S. EPA’s 2027 regulations a full year early.
Cummins intends to release the diesel version of the X10 first, with other versions for gaseous fuels coming to market 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,” said José Samperio, executive director of 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.”
Samperio said that the X10 features the ratings and reliability to complete the toughest jobs and repeated a familiar Cummins talking point these days: That diesel fuel and diesel engines will remain a critical technology for the commercial vehicle market for years to come, and Cummins will continue to support those markets and applications as long as necessary.
Cummins said the new X10 diesel will emit 75% less NOx emissions than required at launch in 2026. It will also be compliant to the U.S. 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, a telematics system 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 Engine Platform
The new X10 engine is built on Cummins’ emerging fuel agnostic engine 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.
Samperio added that the new X10 engine will first be available in Europe and North America, although it will be introduced in other regions over time and will eventually be engineered for off-highway markets as well.
For more information on Cummins technologies today, check out this HDT Talks Trucking Podcast with HDT editors Jim Park and Jack Roberts discussing what they learned during their visit to Cummins headquarters in the summer of 2023.
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