For a long time simultaneous improvements of seemingly contradictory tire properties, e.g. rolling resistance, wet grip, winter performance and service life have been the major request from automobile manufactures especially for original equipment (OE) tires. It was only in the beginning of the nineties that these demands could be met using tread compounds with special polymers and high loadings of silica (together with silanes) instead of carbon black. The properties of these compounds strongly depend on the precipitated silica used. An optimum specific surface area could be derived by critically monitoring Mooney viscosity and dynamic stiffness. The effect of silanol group density, moisture content and surface activity on important in-rubber-properties is shown.