A new alkoxysilane was used to reduce the hydrophilic character of the silica used in reinforcing styrene/butadiene elastomers for the tyre industry. The surface properties of silica modified with 17 wt.‐% of this silane were estimated by inverse GC. A clear change from hydrophilic to hydrophobic character was observed. Styrene/butadiene copolymers loaded with modified silicas were characterized were characterized using vulcanization tests, stress/strain measurements and morphological analysis. The best tensile properties were obtained with TESPT‐modified silica. The properties of the compound loaded with sb1‐pre‐grafted silica are scantily lower that the ones of the other compounds. This difference must be ascribed to a higher crosslink density given by the sulfur deriving from the TESPT decomposition during the vulcanization process. magnified image