An oil pump is an important component of the automotive powertrain, which can potentially help improve fuel economy and reduce greenhouse gas (GHG) emissions. This can be achieved not only through a lightweight design, but also through an increase in engine efficiency by drawing the optimal amount of energy for its operation. This paper discusses the engineering design and development of a plastic automotive engine oil pump as an alternative to current metal oil pumps. Detailed component design features to ensure the working of the plastic pump under harsh chemical, temperature and vibration environment are discussed. The proposed design integrates several parts and uses unique plastic design elements to improve upon current metal design. Innovative joining methods and assembly sequencing are implemented to maintain pump efficiency and functional precision. Use of self-lubricating plastics to increase engine efficiency by reducing wear between moving parts is explored. Data and findings from extensive structural and processing simulations, as well as high temperature and long-term material tests, carried out during the design phase to ensure structural integrity and manufacturability are included. The proposed plastic oil pump design is found to significantly reduce weight, cost and part count while maintaining equivalent structural integrity at high operating temperatures.