Innovative Advances in Electric Vehicle-Driveline Lubrication: Optimizing Lubricants for Enhanced Efficiency and Sustainability

Abstract The global reduction of CO2 emissions, including from the transportation sector, is critical for addressing climate change. New electric vehicles (NEVs) are pivotal in this effort, with battery electric vehicles (BEVs) being a primary focus, due to their potential for significantly reducing emissions. This study investigates the efficiency of selected lubricants in the context of an electric axle (E-axle) drivetrain, a key component in BEVs. Compared with conventional vehicles, driveline efficiency may be viewed as even more essential for the BEV. Here, all aspects of efficiency are essential to improve delivery from the main drive battery capacity, reduce vehicle weight, and improve overall performance. By testing different fluids and formulations, this research identifies significant efficiency gains from the E-axle, which directly contribute to enhancing the range, whilst reducing the operational costs. Using a typical E-axle, the study practically demonstrates that the targeted selection and optimization of lubricant can achieve worthwhile efficiency improvements. It is expected that efficiency gains are possible with other motors and drivetrains. However, each system requires individual optimization to realize such benefits. This research demonstrates the importance of customizing lubricant solutions to the specific demands of each drivetrain, thereby supporting the broader adoption of more efficient and sustainable electric vehicle technologies.