High-fidelity terramechanics models provide detailed representations of tire–terrain interaction but can be computationally demanding for real-time and vehicle-level simulations. This study presents a computationally efficient lookup table-based approach for predicting longitudinal tire forces on deformable terrain. A Hybrid Soft Soil Tire Model (HSSTM) is employed as the high-fidelity reference model to generate longitudinal tire force data over selected combinations of longitudinal slip ratio and vertical load. The resulting force characteristics are organized into a multidimensional lookup table, where interpolation is used to estimate longitudinal force at operating conditions not explicitly included in the original dataset. The accuracy of the reduced-order representation is evaluated by comparing the interpolated forces with corresponding HSSTM predictions at selected operating points. In addition, the computational efficiency of the lookup-table model is assessed to investigate its suitability for real-time vehicle dynamics applications. The proposed approach preserves the primary nonlinear characteristics of longitudinal tire force generation while avoiding repeated high-fidelity tire–terrain calculations. The results demonstrate the potential of lookup-table representations to bridge detailed terramechanics modeling and computationally efficient off-road vehicle simulation.