Twentyfour years have gone by since the publication of K. Lohner and H. Muller’s comprehen- sive work Gemischbildung und Verbrennung im Ottomotor in 1967 [1.1]‘ Naturally, the field of mixture formation and combustion in the spark-ignition engine has wit- nessed great technological advances and many new findings in the intervening years, so that the time seemed ripe for presenting a summary of recent research and developments. There- fore, I gladly took up the suggestion of the editors of this series of books, Professor Dr. H. List and Professor Dr. A. Pischinger, to write a book summarizing the present state of the art. A center of activity of the Institute of Internal-Combustion Engines and Automotive Engineering at the Vienna Technical University, which I am heading, is the field of mixture formation -there- fore, many new results that have been achieved in this area in collaboration with the respective industry have been included in this volume. The basic principles of combustion are discussed only to that extent which seemect necessary for an understanding of the effects of mixture formation. The focal point of this volume is the mixture formation in spark-ignition engines, covering both the theory and actual design of the mixture formation units and appropriate intake manifolds. Also, the related measurement technology is explained in this work.