1. For use with a vehicle having a torque-based speed control system which controls an internal combustion engine to control the speed of the vehicle, a method for controlling the internal combustion engine for a plurality of operating modes including an initial entry into speed control mode and a plurality of transitional dynamic operating modes, the method comprising: determining an actual vehicle acceleration; determining an actual wheel torque; determining an initial desired wheel torque based on the actual vehicle acceleration and the actual wheel torque; and controlling torque generated by the engine based on the initial desired wheel torque so as to smoothly control the speed of the vehicle upon said initial entry into speed control mode and upon transitions between said dynamic operating modes.