The tech driving performance with the X10 under the hood

The old notion that there is no replacement for displacement has met its match in a compelling new solution by Cummins in its Cummins HELM™ 10-liter platform.  

The Cummins X10 diesel engine is engineered to offer a smarter, more capable alternative to both the larger X12 and the slightly smaller L9 engines it will replace.

Some longtime users of the X12 may take note of the downsizing, but Cummins engineers say their latest work has the X10 punching well above its displacement.

Cummins’ larger and more efficient 7th generation variable geometry turbocharger, more efficient combustion, greater compression, improved engine cooling, upgraded fuel system, a new 48-volt aftertreatment system work together to deliver a class-leading power-to-weight ratio. 

Described as a versatile workhorse, the new engine has impressive muscle with up to 475 horsepower and 1,650 lb.-ft. torque. For some, that may prove too much. No problem. The ability to leverage  Cummins’ consultative sales approach will help to ensure that fleets and owner-operators get the most effective rating for their tough jobs.  

While some in the industry have wondered how the X10 would compare to the X12 in terms of braking, Cummins says the new design not only meets expectations but surpasses them.

The engine brake delivered by Jacobs Vehicle Systems uses a one-and-a-half or two-stroke design that opens the valve on both the compression and exhaust strokes to generate greater braking force. This design allows the X10 to produce up to 475 horsepower of braking, an increase over the X12’s peak of 390 horsepower. 

Drivers can expect braking performance that feels comparable to an even larger engine. They will also be braking with less weight provided by a sculpted block and head. 

The X10 also features advanced Power Take-Off (PTO) capabilities. The improved PTO delivers 590 lb-ft continuous and up to 664 lb-ft intermittent power. 

Cummins X10 presents an impressive evolutionary step that is not surprising given its close lineage to the X12 and L9. 

“This is not just a clean sheet engine,” said Tara Johnson, Cummins North America On-Highway X10 Product Manager. “This is 40-plus years of knowhow that we have, between the X12, the L9 and its predecessor the 8.3. We've got all of that knowledge built in.”

Cummins experts are confident that knowledge has delivered a product that will resonate with customers. Many engineers behind the X12 contributed to the development of the X10, drawing on deep institutional experience. Built on a globally validated platform, the X10 represents a natural evolution, according to Cummins—refining proven strengths while introducing key improvements tailored for the North American market.

Reducing emissions and complexity

Emissions reduction in the X10 starts with improved fuel efficiency through an upgraded 2200 bar fuel system, a new piston bowl and higher compression ratio. 

“It's about 4% better fuel economy than the L9 and up to 2% better versus the X12,” Johnson said. 

A modified aftertreatment system on the X10 further reduces emissions. A 48-volt alternator under the hood powers grid heaters in two modules. This approach delivers more consistent aftertreatment temperatures to better reduce emissions across all duty cycles. 

The system was designed for durability and ease of maintenance, beginning with a dedicated belt-driven alternator that eliminates the need for lithium-ion batteries. To ensure long-term performance, the alternator is cooled by circulating coolant rather than relying on air cooling—an approach intended to support operation over 11 years or 650,000 miles without service.

Aside from the heated, twin-module selective catalytic reduction (SCR) modules, aftertreatment on the X10 is not a big departure from systems on the L9 and X12. A simple but effective design means less to monitor and maintain. 

The familiar configuration includes the same size diesel oxidation catalyst, diesel particulate filter, mixer and doser found in single-module systems. The SCR was expanded and split into dual parallel flows to improve airflow, but the overall design minimizes the need for sensors, communication networks and fault monitoring, reducing complexity for operators and technicians alike.

Easier maintenance and service delivered 

Cummins engineers looked ahead to lowering costs and increasing productivity over the long haul through regular maintenance and close engine monitoring. 

New cartridge-style designs for the X10 make oil and fuel filter changes less costly, easier and safer on the environment. A large oil pan design pushes out oil drain intervals.

Easier overhead cam access will greatly reduce service times during rebuilds for high-mileage equipment. 

Close engine monitoring through Cummins Acumen hardware and Connected Solutions helps with uptime and long-term engine health. Service events and system updates can be prioritized and planned to help drivers and service personnel maximize their time. 

“We want customers to be able to concentrate on the mission critical work while Connected Solutions handles most of the administrative and triaging work,” Johnson said.

The X10 is designed to handle demanding duty cycles across a range of applications. With its updated architecture and focus on performance, durability and adaptability, the engine reflects Cummins’ continued effort to meet the evolving needs of commercial fleets in a variety of conditions.