Preface

If we want to continue to offer our customers vehicle drive systems that unite key characteristics such as low fuel consumption, impressive driving dynamics, flexibility in use, and high comfort combined with the sustainable use of resources and the lowest exhaust emissions, then we’re going to have to ramp up our development budgets. Current market trends, which are seeing a decline in registrations of vehicles with diesel engines, are increasing the pressure to develop high-efficiency gasoline engines. As a bridging technology, the gasoline engine will be a key determinant of our car fleet’s consumption in the coming years. Further increases in efficiency, however, will be limited by the well-established phenomenon of gasoline engine knock. This conference thus addressed one of the most important issues in the ongoing development of the gasoline engine. The majority of today’s high-efficiency gasoline engines utilize downsizing or combine high mean pressures with Miller cycles and increased geometric compression, known as “rightsizing.” When designing engines for high compression ratios—an essential requirement for efficiency increases—the knock limit is the defining criterion. In addition, the rise in specific torque at very low speeds as the basis of low fuel consumption, assisted by downsizing and downspeeding, has long been associated with the preignition phenomenon. Ideal efficiencies are achieved by charge dilution combined with very high compression. This, however, causes “extreme knock,” potentially leading to catastrophic events in the midto high-speed range. Improving charge-diluted concepts demands a greater focus of research in this field. The introduction of RDE legislation this year will further grow the requirements for combustion process development, as residual gas scavenging in the low-end torque range and enrichment to reduce knock and exhaust temperatures will be legally limited. There is still, however, the need to reach the center of heat release with the highest possible compression. Preventing damage to high-efficiency gasoline engines demands a deep understanding of the phenomenology and precise