<p>This paper proposes an analytical method that incorporates stator inner-diameter tolerance effects for efficient tolerance analysis of a Surface Permanent Magnet Synchronous Motor (SPMSM) with a segmented stator core used in an automotive Electric Power Steering (EPS) motor. Although segmented stator cores can improve output power density by enabling a high slot fill factor, assembly tolerances caused by coil-to-coil interference can degrade the stator roundness. This deterioration distorts the air-gap permeance, leading to increased cogging torque and, consequently, worsening torque ripple. Accurate cogging torque prediction under such assembly tolerances typically requires a large number of electromagnetic analyses; however, the Finite Element Method (FEM), which is commonly employed for this purpose, involves substantial computational cost. To address this issue, the proposed approach calculates the air-gap flux density and predicts the cogging torque using Space Harmonic Analysis (SHA) together with a Complex Relative Permeance (CRP) function that accounts for tolerance effects. The effectiveness of the proposed method is validated by comparison with FEM-based results and experimental data obtained from a prototype motor.</p>