1. An engine speed control method for controlling engine output torque in accord with an engine torque requirement determined as the torque required to drive engine speed toward a target engine speed, comprising the steps of: storing a predetermined schedule of estimated steady state torque requirement values as a function of a predetermined engine operating condition; determining the current engine operating condition; referencing, from the stored schedule, a current estimated steady state torque requirement as a function of the current engine operating condition; estimating steady state torque requirement error; adjusting the current steady state torque requirement in direction to minimize the estimated steady state torque requirement error; and controlling engine output torque in accord with the adjusted current steady state torque requirement.