The new exhaust emission requirements introduced by governments about light duty vehicles are becoming very tightening. As well as reaching legal emission limits, the car manufacturers must improve the fuel efficiency lowering average fleet CO2 value and also continue to improve the fun to drive. The Hybrid and Diesel propulsion systems are two important players on that competition. 48V hybrid is a cost-effective solution despite HV system and it could outline a new way to approach the well-known trade-off between CO2 and NOx on Diesel engine. The aim of this study is to investigate and measure how 48V Hybrid System could improve the engine efficiency, reduce the exhaust emission on new WLTP cycle and strengthen the performance of 7- seat multi purpose vehicle equipped with 1.6L Diesel engine. As system interactions strongly affect the results, prototype propulsion systems has been developed and assembled to test and measure the overall benefits and to explore the further benefits coming from a holistic approach.