<p>This study focuses on lightweighting spur gears by incorporating cellular structures within their design. Numerical simulations are performed based on a Finite Element Model for the spur gear designs integrating six different cellular structures into their core zone. Two designs of experiments (DoE) were carried out to analyze the mechanical performance of the spur gears with the cellular structures. The first one aims to confirm the impact of the volume fraction and the type of cell structure on the mechanical behavior. In the second one, volume fraction and the number of cells in the radial, azimuthal, and axial directions were used as parameters for the DoE to evaluate their effects on the mechanical responses. The results show a strong dependency of all the design parameters on the von Mises stress and total displacement of the spur gears. Nevertheless, it was found that depending on the cellular structure, stress minimization can be achieved by a combination of two design parameters, prevailing as the most critical parameter, the volume fraction for almost all structures. This investigation demonstrates that using cellular structures in spur gears can achieve substantial weight reduction while maintaining a robust mechanical performance.</p>