Hydrogen-Gasoline E10 operation in the Series-Manufactured internal combustion engine at partial load

In response to increasingly stringent automotive CO 2 emission standards, researchers are exploring approaches to reduce CO 2 by blending carbon-free fuels with conventional gasoline. This study evaluates the effect of hydrogen addition on the performance and combustion thermodynamics of a series-production gasoline spark-ignition engine, focusing on heat-release rate, combustion phasing, and knock intensity, over a hydrogen share of 0 – 50 % by mass. Experiments were performed on a Nissan HR16DE passenger-car engine at a stoichiometric partial-load operating point (2500 rpm, IMEP 520–530 kPa), representing a stabilized mid-speed condition typical of everyday driving. The results show that increasing the hydrogen share requires retarding the spark timing to maximize indicated mean effective pressure. Brake thermal efficiency improved slightly, although a small decrease was observed at the highest hydrogen share. CO 2 emissions decreased proportionally to the hydrogen fraction in the fuel. Overall, hydrogen shortened the ignition delay, increased peak in-cylinder pressure, and no harmful knock was observed under the tested partial-load conditions. The distinguishing features of this work are the broad hydrogen range, independent hydrogen and gasoline dosing, and spark-timing optimization for each blend. The recommended hydrogen share is 20–59 % on an energy basis (10–33 % by mass). At optimal operation, the combustion center (CA) shifted to approximately 6 °CA ATDC, which can be used as a reference for spark-timing calibration. Accordingly, updating spark timing maps in the engine control software is recommended.