48 V mild hybrid electric vehicles (MHEVs) are considered to the prospective near-term solution for cost-effective vehicle electrification. In this study, the fuel consumption improvement of various synergistic engine technologies was experimentally investigated with a 48 V P0 mild hybridization. The details of application and optimization for each technology were considered and the effect of each technology was quantitatively identified. A combination of synergistic engine technologies including a high compression ratio, late intake valve closing strategy, high tumble flow, electric supercharging and exhaust gas recirculation was applied to a 1.4 L PFI engine. Engine test results confirmed that fuel consumption could be significantly improved by these technologies, and the maximum power and torque were increased as well. The vehicle test results showed that the application of synergistic engine technologies improved vehicle fuel economy by 10%. Engine optimization and EGR could enhance the fuel economy by 5.5% and the effect of electric supercharging and downspeeding resulted in a 4.5% fuel economy improvement. These improvements through the engine technologies were greater than the effect of 48 V mild hybridization which was verified to be 5.5% of the fuel economy enhancement. The result suggests that the application of synergistic engine technologies will be highly effective for improving fuel efficiency of MHEV.

48 V 轻度混合动力电动汽车 (MHEV) 被认为是具有成本效益的车辆电气化的前瞻性近期解决方案。在这项研究中，通过 48 V P0 轻度混合动力对各种协同发动机技术的燃油消耗改进进行了实验研究。考虑了每种技术的应用和优化细节，并定量识别了每种技术的效果。1.4 L PFI 发动机结合了协同发动机技术，包括高压缩比、延迟进气门关闭策略、高滚流、电动增压和废气再循环。发动机测试结果证实，这些技术可以显着改善油耗，同时也提高了最大功率和扭矩。整车试验结果表明，协同发动机技术的应用使整车燃油经济性提高了10%。发动机优化和EGR可将燃油经济性提高5.5%，电动增压和减速的效果使燃油经济性提高4.5%。这些通过发动机技术实现的改进大于 48 V 轻度混合动力的效果，后者被证实为燃油经济性提升的 5.5%。结果表明，协同发动机技术的应用将非常有效地提高MHEV的燃油效率。燃油经济性提高 5%。这些通过发动机技术实现的改进大于 48 V 轻度混合动力的效果，后者被证实为燃油经济性提升的 5.5%。结果表明，协同发动机技术的应用将非常有效地提高MHEV的燃油效率。燃油经济性提高 5%。这些通过发动机技术实现的改进大于 48 V 轻度混合动力的效果，后者被证实为燃油经济性提升的 5.5%。结果表明，协同发动机技术的应用将非常有效地提高MHEV的燃油效率。