Cummins Validates Its Natural Gas, Variable Speed Technology for The Hydraulic Fracturing Market Through Field Test Operations

Cummins Inc. (NYSE: CMI) continues to advance natural gas technology for hydraulic fracturing applications as the HSK78G engine demonstrates its proven capability in the field. The development, announced in 2025, is the defining engine within Cummins SPP™ portfolio, a range of Spark-Ignited Pumping Power solutions, establishing the performance, efficiency, and integration benchmarks that will guide future offerings tailored for well-servicing applications. Designed to deliver a high power density with industry-leading fuel efficiency and a compact footprint, the 12-cylinder, 78-litre HSK78G delivers up to 3,000 brake horsepower. The final development of this solution continues with Liberty Energy Inc., most recently through extensive testing activities.

The HSK78G engines have accumulated significant operating experience across a combination of test cell validation and demanding frac field operations, totaling more than 10,000 hours. This activity has focused on validating durability, load response, and integration within active operations, with duty-cycle data reinforcing consistent performance and reliable operation in dynamic environments. Designed to lower fleet emissions, the HSK78G will balance optimized fuel efficiency and the requirements for EPA Mobile Off-Highway Tier 2 compliance, without compromising on practical performance.

“EPA certification is a major milestone for the HSK78G program, and we remain on track for approval in Q2 of 2026,” Jiabo Zhang, North American Oil and Gas Leader at Cummins, shared. “Certification will allow us to expand deployment, support additional fleets, and continue validating the solution across a broader range of operating conditions.”

The program is now focused on the final variable-speed configuration, currently being validated by fleet level units deployed in the field. This configuration enables a more precise alignment between engine output and operational demand, supporting improved efficiency, reduced component wear, and enhanced flexibility across varying operating conditions. These capabilities represent a defining differentiator for the HSK78G platform against current industry offerings, as it transitions from development into a fully realized solution for the market.

As additional HSK78G units are supplied for fleet-level operation, the program continues to move toward wider applications across hydraulic fracturing environments. Together, these milestones reinforce the HSK78G’s position as the industry’s first and only variable-speed, large-displacement natural gas engine specifically tailored for hydraulic fracturing applications. Delivering a unique combination of power density, efficiency, and lower emissions in a recognizable platform, this platform further reflects Cummins’ commitment to advancing technology and innovation for the oil and gas market.

Discover more about the HSK78G engine.