A door closer with an electric motor-assisted closing feature, that may generate its own power to assist in closing, and controls the speed of opening and closing of the door during generation. A motorized door closer that electrically creates a latch boost force for a closing door. The door closer includes a motor disposed to operatively connect to a door so that the door will moved toward closed when the motor moves, and a position sensor to determine a position of the door. A processor is programmed to exert a closing force on the door in the latch boost region or when it otherwise detects that a motor assist is needed. The door closer may be regenerative with respect to power and may be self-adjusting with respect to the latch boost/motor assist force applied and control of closing speed and opening speed. A