Provided that a more electric engine (MEE) is equipped with electrical machines connected to each of its shafts, using power electronic converters within a common high voltage DC bus configuration, it is possible to redistribute a desired amount of power between the engine shafts. This paper presents the impact of electric power transfer (EPT) on engine performance by using a developed 0-dimensional engine model based on the inter component volume (ICV) method and generic engine component maps, scaled to match the design point of the CFM56-3 engine. Validating the simulation results with engine performance data shows that the steady-state error of the speed and fuel consumption is within 1% and 3% for the high- and low- speed settings respectively, which is acceptable for the EPT studies. Detailed simulation results from the engine model and EPT weight penalty analysis show that, fuel consumption for short- and medium-haul flights reduces by up to 0.46% and 0.79% with state-of-the-art, and 0.60% and 1.0% with future technologies, respectively. It is shown that a 400 kW EPT system is optimum for the CFM56-3 engines, which can halve the amount of bleed air from variable bleed valves (VBVs). However, for the VBVs removal, a higher amount of power transfer is required. Furthermore, results show that power transfer can increase the surge margins significantly at low speed settings and can also recover the surge margins of degraded engines at high speed settings.