Improving transaxle efficiency is vital for enhancing the overall performance and energy economy of electric vehicles. This study presents a systematic approach to minimizing power losses in a single-speed, two-stage reduction e-transaxle (standalone) by implementing a series of component-level design optimizations. The investigation begins with the replacement of conventional transmission oil with a next-generation low-viscosity transmission fluid. By adopting a lower-viscosity lubricant, the internal fluid resistance is reduced, leading to lower churning losses and improved efficiency across a wide range of operating conditions. Following this, attention is directed toward refining the gear macro-geometry to create a gear set with reduced power losses. This involves adjustments to parameters such as module, helix angle, pressure angle, and tooth count, along with the introduction of a positive profile shift. These modifications improve the contact pattern, lower sliding friction, and achieve a more uniform distribution of forces along the gear flanks. As a result, load-related gear losses are significantly diminished. In the final stage of optimization, high-performance, low-friction bearing designs are incorporated to further reduce mechanical drag and enhance overall drivetrain efficiency. For bearing loss optimization strategies, energy-efficient ball bearing designs is examined and engineered to lower internal friction and increase operational lifespan. Energy Efficient bearing prove significant improvement in efficiency and further reducing mechanical losses within the drivetrain. Taken together, the findings highlight that careful selection of lubricants, refinement of gear geometry, and adoption of advanced bearing solutions can deliver notable gains in transaxle efficiency. These outcomes reinforce the potential of such targeted interventions as practical means for boosting drivetrain performance in electric vehicle applications.