Current significant challenges in the automotive industry for increasing fuel economy and reducing CO₂ emissions remain with traditional combustion engines. Moderately small increases in fuel efficiency lead to major reductions in CO₂ emissions, primarily due to large production volumes utilizing incremental fuel saving technologies.Enhancements of today's vehicle powertrains, including micro-hybrids and mild-hybrids with stop-start systems, and coasting and energy recuperation have shown a positive cost benefit and shorter payback period. This is identified when the technology is compared to more complex and expensive HEVs (Hybrid Electric Vehicles) and BEVs (Battery Electric Vehicles).This paper describes the development of a baseline conventional vehicle model for estimating fuel savings and CO₂ reduction; it provides a benchmark for the development of fuel saving energy management technologies such as stop-start, coasting, and dual voltage architecture with regenerative braking and "on-demand" fuel senders. It will be shown that a stop-start system will provide a simulated 2.9% FE (Fuel Economy) benefit for the EPA unadjusted combined city/highway driving cycles. Also enhanced stop-start with aggressive coasting with engine-off (≺100 km/hr) provides an additional benefit of 7.1%.In addition, this paper describes a case study for the development of a HIL (Hardware-In-the-Loop) simulator which makes use of the conventional baseline model. The HIL system measures fuel savings of replacing a "100% driven" fuel system with an "on-demand" fuel delivery system. The case study will show a 40% CO₂ reduction over "100% driven" DC pump with a DC "on-demand" pump and an additional 22% CO₂ reduction for the BLDC "on-demand" pump for the EPA city/highway driving cycles using a Mini Cooper vehicle model.