The electrification of the internal combustion engine is an important subject of future automotive technology. By using a motorized internal combustion engine, it is possible to recover waste energy by regeneration technology and to reduce various losses that deteriorate the efficiency of the internal combustion Engine.This paper summarizes the results of the development of an engine-integrated motor that can be applied to a 48V mild hybrid system for motorization of an internal combustion engine. Like the 48V MHSG-mounted mild hybrid system designed to replace the generator in the auxiliary belt system, the motorized internal combustion engine is designed with the scalability as the top priority to minimize the additional space for the vehicle and to mount the same engine in various models.The addition of an integrated motor to the crankshaft instead of the MHSG of a belt-driven mild hybrid system that replaces the generator will allow the removal of components with redundant functions, starters, etc. and the accessory belt system. The motor mounted on the crankshaft also helps to effectively overcome the disadvantages of the engine, which was difficult to overcome in the real driving.The use of powertrain motorization technology is expected to further reduce the energy discarded by real-time information generated on the road while driving by integrating future inter-vehicle communication or autonomous driving technology with internal combustion engines. It is necessary to improve the efficiency of internal combustion engines and improve the motorization to make up for the shortcomings until the future technology is established, which enables hydrogen or electricity production to be eco-friendly without generating GHG or using fossil fuels.