Driven by stricter mandatory regulations on fuel economy improvement and emissions reduction, market penetration of electrified vehicles will increase in the next 10 years, among which mild hybrid will become a leading sector in growth. Researchers forecast the sales of mild hybrid vehicles will reach 1.4 million units per year by 2020, and 7 million units by 2024. The high cost of HEVs has somewhat limited their widespread adoption, especially in developing countries. Conversely, it is these countries that would benefit most from the environmental benefits of HEV technology. Compared to a full hybrid, a plug‐in hybrid or an electric vehicle, a mild hybrid system stands out due to its maximum benefit/cost ratio. As part of our ongoing project to develop a mild hybrid system for these markets to improve the drive performance and efficiency. High power density ultra-capacitors are incorporated for fast charging and discharging during the acceleration and other operations. In this paper, The fuel economy of a conventional vehicle and mild hybrid electric vehicle are compared in this paper. This analysis includes vehicle modelling and simulation. Fuel economy is assessed and referenced with standard drive cycles provided by the U.S Environmental Protection Agency. Results demonstrate the benefits of a lower ongoing cost for the HEV architecture. These benefits include torque-hole filling between gear changes, increased fuel efficiency and performance. Index Terms- Ultra capacitor battery, Modeling; Fuel economy; Mild hybrid electric vehicle (MHEV); Powertrain; References 1. A. R. Salisa, N. Zhang, and J. Zhu, "A comparative analysis of fuel economy and emissions between a conventional HEV and the UTS PHEV," IEEE Transactions on Vehicular Technology, vol. 60, pp. 44-54, 2011. 2. Heath, R. & Child, A. 2007, 'Zeroshift. A seamless Automated Manual Transmission (AMT) with no torque interrupt', Int. Cong. & Exposition-SAE Technical Paper, pp. 1-6. 3. Ehsani, M., Gao, Y. & Emadi, A. 2009, Modern electric, hybrid electric, and fuel cell vehicles: fundamentals, theory, and design, CRC press.