This manuscript describes the development and optimization of sol-gel SiO2 -based Hybrid-Organic-Inorganic (HIO) coatings for application as corrosion protective layer on rotors employed in disc brake systems. The corrosion protection achieved with the coatings is optimized by tuning their water wettability, surface free energy (SFE), thickness and cross-linking degree, which strongly depend on sol chemical composition. Optimal film features are obtained modifying the silica network with organic components and accurately tailoring the deposition parameters. In particular, a Design of Experiment (DoE) approach is used to optimize the composition of the coatings and thereby their corrosion protection capability. Anti-corrosion properties of the coatings are assessed by means of the voltammetry probe: the corrosion potential and corrosion current, as obtained from Tafel curve fitting, are used as figures of merit. Their correlation with synthesis parameters such as silica concentration, inorganic/organic silane ratio and film thickness are widely discussed to determine the most relevant factors in the production of such coatings as protective layers for braking discs.