Methods, systems, and devices for operating an internal combustion engine at a firing fraction that is less than a value of 1.0, wherein one or more cylinders of the internal combustion engine are not designated to be fired, determining a smoothing event time period where a particular one of the cylinders that have not been designated to be fired is either skipped or recharged, selecting a periodic disruptive waveform to approximate that is related to a skip or recharge event that is part of the smoothing event time period, determining a first harmonic sinusoid from a group of harmonic sinusoids that reduces the error between an approximated waveform and the disruptive waveform, determining a timeframe for utilizing the first harmonic, and actuating an additional motor to initiate a supplemental quantity of torque during the smoothing event time period based on the disruption quantity of torque.