Technology Developments systems further support wear resistance, while flexible mounting options and integrated aftertreatment systems are designed to simplify installation and reduce overall system complexity.
Liebherr is also exploring next-generation engine concepts, with the reveal of the D9612 high-performance combustion engine at bauma 2025. The 12-cylinder engine is rated for 1,494 horsepower and engineered specifically for mission-critical power generation applications in demanding operating conditions. Development of the D9612 focused on balancing performance with improved fuel consumption and reduced emissions, reflecting a broader industry effort to maintain high power density while meeting strict environmental regulations.
Fuel Flexibility
While diesel still reigns, the industry is also seeing a trend toward fuel flexibility. Cummins higher efficiency, lower emissions and multiple fuels( HELM) platforms, which include the 2024 X15 as well as the X10 and B series, aim to reduce emissions while promoting cleaner technologies. Cummins notes that the ability for businesses to choose their fuel types is a“ game changer” when adopting cleaner fuels, as it won’ t require a complete overhaul of fleets.
At the core of this approach is a common engine base that remains consistent across platforms, while key components such as cylinder heads and fuel systems are tailored to specific fuel types. This allows the same fundamental engine architecture to support alternative fuel types without requiring a completely different engine design.
Fuel options under the HELM platform include advanced diesel, natural gas and hydrogen, giving original equipment manufacturers( OEMs) and equipment owners a wider range of pathways as regulations and fuel availability continue to vary by region. This flexibility is increasingly important as manufacturers work to meet Stage V emissions requirements and prepare for future compliance standards.
Hydrogen Moves Closer
Next in line for off-highway equipment, hydrogen combustion is on its way to becoming a more practical alternative in the industry.
The Cummins B6.7H for off-highway applications is a hydrogen platform with a top rating of 290 horsepower and 885 footpounds( 1,200 newton-meters) of peak torque for Stage V / Tier 5 applications. The engine is designed to appeal to manufacturers by leveraging much of the same core hardware and systems used in diesel platforms, including compatibility with existing transmission, cooling and hydraulic systems. This approach helps reduce integration complexity for OEMs, making it easier to adapt existing machine architectures to lower-emission fuel options without major redesigns.
Liebherr’ s compact, off-road H966, also on display at bauma 2025, is a six-cylinder hydrogen engine prototype, still in development. It features port-fuel technology( PFI) and has close to“ zero” NOx and CO2 emissions. Liebherr describes the engine as the“ sweet spot” between combustion engine developments and advanced technologies that optimize hydrogen combustion. This approach is simultaneously directed at both performance and emissions.
Building on that direction, Liebherr is also developing a hydraulic air booster system with potential applications in future alternative-fuel engines. The system recovers hydraulic energy and uses it to drive a mechanical compressor when needed, helping improve response and efficiency under varying load conditions.
The Liebherr D9612 combustion engine is rated at 1,494 horsepower for demanding off-road applications.
For hydrogen engines, it could support the high excess air requirements needed for stable combustion, while also improving transient performance to better match diesel-like response. Similar benefits could extend to other alternative fuels, such as ammonia, where reduced engine speeds and improved efficiency may help lower overall fuel consumption while maintaining usable power output.
These developments across the industry exemplify that hydrogen and other alternative fuels are moving beyond just concept stages and into more practical applications, where performance and efficiency are addressed in parallel.
Multiple Paths Forward
Engine development in the crane and heavy-equipment sectors is no longer focused on a single solution or direction. While diesel engines remain central to heavy-duty applications, there is a clear shift toward cleaner, more efficient platforms. Hydrogen, renewable fuels and alternative combustion technologies are still early in their development, but continue to advance as regulations evolve and emissions targets tighten.
With this image in mind, future engines and drive systems will likely prioritize flexibility, allowing equipment owners and operators to adapt to changing regulations, fuel availability and operational demands without compromising the performance they have come to rely on and expect.
www. cranehotline. com • July 2026 21