It is well known that rubber silanes are used as coupling agents which are necessary to achieve a high degree of reinforcement in silica-filled rubber compounds. The silanes establish not only a covalent link between the silica particle and the rubber matrix, but also improve compound processability and reduce the silica-silica network resulting in a lower Payne-effect. This paper highlights the development stages in the field of rubber silanes to improve processability, increase coupling efficiency and reduce the emission of VOC's. The reaction mechanism of the functional groups is key to achieving the highest efficiency and should be considered. This paper presents our latest findings, to combine high reactivity with good processability, offering the compounder a tool to further optimize their recipe. Presented by Hans-Detlef Luginsland, Ph.D., Global Marketing, Evonik Industries AG.