As fuel economy becomes increasingly important in all markets, complete engine system optimization is required to meet future standards. In many applications, it is difficult to realize the optimum coolant or lubricant pump without first evaluating different sets of engine hardware and iterating on the flow and pressure requirements. For this study, a Heavy Duty Diesel (HDD) engine was run in a dynamometer test cell with full variability of the production coolant and lubricant pumps. Two test stands were developed to allow the engine coolant and lubricant pumps to be fully mapped during engine operation. The pumps were removed from the engine and powered by electric motors with inline torque meters. Each fluid circuit was instrumented with volume flow meters and pressure measurements at multiple locations. After development of the pump stands, research efforts were focused on hardware changes to reduce coolant and lubricant flow requirements of the HDD engine. As engine hardware changes were made to reduce coolant and lubricant requirements, the fuel economy benefit was immediately realized. Several hardware sets are discussed along with the resulting reduction in pump parasitic losses. Lastly a comparison is made between the production engine configuration and an optimized setup with several new engine technologies for reduced parasitic losses and increased Brake Thermal Efficiency (BTE).