Gearbox plays a vital role of power transmission in automobiles, it should be as optimized as possible and efficient for divergent power transmission scenarios. In this research paper, an optimum design of a two-stage spur gear system is performed. The optimizations are made so that gearbox can work sublimely on two extreme gear ratios, which will be employed to run on torque and speed drive. The developed optimum design led to a smaller and quieter gearbox compared to its older counterparts. The gearbox is modeled and designed in SOLIDWORKS. Static (Stress, Strain, Deformation and factor of safety) has been carried out on gears using ANSYS tool and SOLIDWORKS flow analysis. Vibrational analysis for gearbox casing is performed using ANSYS.As all the analysis is performed in ANSYS software, the analysis follows finite element methods which gives accurate result by minimizing associate error function. In this paper we have stimulated loading conditions on our design and recorded the design response to those conditions. © IAEME Publication Scopus Indexed.