The silanization of silica-filled compounds containing a blocked mercapto silane, 3-octanoylthiopropyltriethoxysilane (OTPTES), was characterized by evaluating the exposed silica surface covered by the silane. Measurements of silica flocculation upon heating were employed to estimate the exposed silica surface coverage for silanization calculation. Compounds were prepared with various mechanical and thermal histories by adjusting the mixing time and temperature. Dynamic hysteretic properties at 0 and 60 °C in conjunction with strategic mechanical properties were correlated with the degree of silanization for each compound. Well-balanced properties in processability, reinforcement, and performance were readily attained through the study of the silanization/structure/property relationship. Experimental data showed that an 84% degree of silanization was needed to attain the optimal properties of compounds containing OTPTES regardless of the mixing protocol. Consistent compound properties may be realized by using a designated degree of silanization as a key mixing parameter for effective quality control in tire production.