A pumpjack is driven by an electric motor coupled to a gear box. A local drive controller controls the motor in accordance with a varying motor speed profile over a pumping cycle of the pumpjack. The drive controller determines, based on sensory feedback from the one or more sensors, a pumping cycle load profile, automatically determines, based on the pumping cycle load profile, a varying voltage profile, and controls the motor in accordance with the varying motor speed profile while applying the varying voltage profile to the motor.