Southwest Research Institute develops hydrogen engine for trucks

The Southwest Research Institute (SwRI) has completed a multi-year development program for a hydrogen-fueled internal combustion engine designed for medium-duty commercial vehicles. Unlike fuel cell technology, this engine burns gaseous hydrogen directly within cylinders using spark ignition.

Engineers optimized the design by transitioning from a single-cylinder prototype to a complete multi-cylinder engine. To match the torque and performance levels of traditional diesel engines, the system utilizes a turbocharger, enlarged intake valves, and specialized hydrogen injection systems. The combustion process produces primarily water vapor, resulting in near-zero carbon dioxide emissions.

By utilizing a combustion-based approach rather than fuel cells, the technology aims to leverage existing industrial ecosystems, including current manufacturing, transmissions, and supply chains. The project was conducted in collaboration with a commercial client and Tier-1 suppliers.