At the 2024 World Internal Combustion Engine Conference held in Tianjin recently, multiple manufacturers showcased diesel engine products with a thermal efficiency of up to 50%. Improving thermal efficiency is one of the important paths for reducing emissions in internal combustion engines. Over the past century, internal combustion engines have provided strong impetus for fields such as transportation, engineering construction, and industrial production. But under the trend of low-carbon transformation in economic development, the internal combustion engine industry is facing unprecedented challenges. Participants unanimously agreed that in the face of the enormous challenges of global energy transformation, internal combustion engines are still irreplaceable in promoting economic and social development. Carbon neutral and zero carbon fuels will revitalize the internal combustion engine industry. "Every year, China's internal combustion engine consumes 60% of the country's oil, and carbon emissions account for about 8-10% of the country's carbon emissions." Li Shusheng, Secretary General of the China Internal Combustion Engine Society, admitted that the internal combustion engine industry is the main force for energy conservation and carbon reduction, and the pressure for energy conservation and emission reduction is not small. Currently, there are multiple technological routes for reducing emissions in internal combustion engines, including improving effective thermal efficiency, using low-carbon and carbon neutral fuels, and advancing governance technologies. "Improving thermal efficiency means that a unit of fuel can generate more useful work, thereby reducing fuel consumption." Zhong Yuwei, Senior Vice President of Yuchai Machinery Co., Ltd., believes that this directly reduces the carbon emissions of internal combustion engines during operation, which helps them maintain competitiveness in the process of energy transformation. However, due to the influence of the high and low temperature limits of the Carnot cycle, improving the thermal efficiency of internal combustion engines is not an easy task. Through continuous innovation in technologies such as high expansion combustion, efficient fuel injection, low resistance friction, and low noise control, the thermal efficiency of diesel engines in China has exceeded 53%, and the thermal efficiency of gasoline engines has also reached 44%. While the thermal efficiency of internal combustion engines continues to improve, the development of zero carbon/carbon neutral fuel technology has opened up a new track for China to achieve the "dual carbon" goal. "The internal combustion engine is just an energy conversion device, which can convert the heat energy generated by fuel combustion into mechanical energy. If the internal combustion engine uses zero carbon fuel, it is zero carbon." Huang Zhen, an academician of the CAE Member, director of the Academic Committee of the 2024 World Internal Combustion Engine Conference, and president of the Smart Energy Innovation Institute of Shanghai Jiaotong University, has won the recognition of many experts in the industry. Hydrogen, ammonia, alcohol based net zero carbon fuels, and biomass fuels are all popular candidates. In order to adapt to new fuels and ensure the safety and reliability of internal combustion engines, corresponding adjustments need to be made to the fuel supply system, ignition system, combustion system, exhaust gas post-treatment, as well as the structure and materials of the internal combustion engine. Shuai Shijin, Executive Director of the China Internal Combustion Engine Society and Professor at Tsinghua University, believes that energy-saving and emission reduction technologies for internal combustion engines have made significant progress in recent years and can meet the world's strictest Euro 7 emission standards. "But to achieve sustainable development of internal combustion engines, the key is how to adapt to the spray combustion requirements of zero carbon fuels such as hydrogen and ammonia, reduce the comprehensive cost of the whole life cycle, improve the thermal efficiency of the engine, etc., and meet the strict emission regulations in the future," said Shuai Shijin. There are also research teams that achieve emission reduction through governance technology. Taking large ocean going cargo ships as an example, due to the need for strong power output, the internal combustion engine power will still remain strong for decades