Chinese company Weichai Power has announced the completion of certification for its new WP15 hydrogen engine under the China VI environmental standard. The manufacturer claims this is the world’s first heavy-duty hydrogen internal combustion engine to achieve compliance with these requirements for commercial vehicles.
The WP15 is a large 14.6-liter power unit delivering 600 horsepower and a maximum torque of 2,800 Nm. During testing, the engine demonstrated a peak thermal efficiency of 46.8%—a level comparable to modern high-efficiency diesel systems and among the best for hydrogen internal combustion engines.
Certification testing took place at the China Automotive Technology and Research Center (CATARC). Engineers evaluated the engine across a wide range of operating conditions, from cold starts and idling to maximum loads and sudden power changes. Based on test results, specialists confirmed compliance with environmental standards, as well as the reliability and stability of the powertrain.
The standout feature of the WP15 is its direct hydrogen injection system into the cylinders. Unlike designs where fuel is delivered through the intake tract, this technology allows for more precise control of the combustion process and reduces the risk of premature ignition and backfires—one of the main technical challenges in hydrogen engines.
Additionally, direct injection enables the use of leaner fuel mixtures, improving hydrogen utilization efficiency and reducing energy losses during engine operation.
In developing the WP15, Weichai prioritized maximum compatibility with existing diesel technologies. According to the company, over 90% of the new engine’s components are shared with its traditional diesel units. This allows it to be installed in heavy equipment with minimal design changes, lowering the cost of transitioning to hydrogen.
Another advantage of the engine is its reduced sensitivity to fuel quality. Unlike hydrogen fuel cells, which require nearly perfectly purified hydrogen, the WP15 can operate on hydrogen of varying purity levels. The company believes this could simplify the creation of storage and refueling infrastructure.
Weichai sees the new engine primarily for heavy transport and industrial use. Potential applications include long-haul trucks, mining dump trucks, port equipment, metallurgical transport, and large hydrogen generator sets.
The company stated that the next step will involve preparing the WP15 for mass production and participating in Chinese hydrogen energy development programs.
It’s worth noting that a hydrogen internal combustion engine should not be confused with hydrogen fuel cells. In the WP15, hydrogen is used as conventional fuel—it burns directly in the cylinders to produce mechanical energy. In fuel cells, hydrogen is not burned but undergoes an electrochemical reaction that generates electricity to power an electric motor.
Weichai’s development shows that China is not only betting on electric vehicles and fuel cells but also on an alternative path—preserving the familiar internal combustion engine architecture adapted for hydrogen. For heavy machinery, where battery weight remains a significant issue, this approach could emerge as one option for transitioning to more eco-friendly transportation.
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