Review of combustion engine efficiency improvements and the role of e-fuels

Over next decade, SI engines might adopt a significant amount of design solutions from CI engines. Therefore none of both can be finally called the winner – they are merging into an optimized engine for future sustainability requirements and heavily depend on technology readiness and technology cost, customer acceptance as well as total cost of ownership assessments. The fuel of choice (e.g. E-methane and E-DME) might determine which engine type can deliver lowest CO2 emissions.