Researchers from Texas-based Southwest Research Institute studied the effects of introducing hydrogen on a diesel engine that had not been optimised for its use and found no short-term noticeable change in engine operation.

Christopher Stoos, Lead Engineer at the Locomotive Technology Center, Southwest Research Institute, presented the results of the testing of hydrogen fuel on a US EPA Tier 2 Caterpillar 3512 mine haul engine at CIMAC 2023. His research team found that, without optimising the control system or adjusting the diesel injection timing, the engine was able to use hydrogen as a supplemental fuel without noticeable change to engine operation.