For decades, scientists and engineers have been working to increase the efficiency of internal combustion engines. For spark-ignition engines, two technical questions in particular are always in focus: 1. How can the air/fuel mixture be optimally ignited under all possible conditions? 2. How can undesirable but recurrent early and self-ignitions in the air/fuel mixture be avoided? Against the background of the considerable efficiency increases currently being sought in the context of developments and the introduction of new fuels, such as hydrogen, methanol, ammonia and other hydrogen derivatives as well as biofuels, these questions are more in the focus than ever. In order to provide a perfect exchange platform for the community of combustion process and system developers from research and development, IAV has organized this combined conference, chaired by Marc Sens. The proceedings presented here represent the collection of all the topics presented at the event and are thus intended to serve as an inspiration and pool of ideas for all interested parties.