The relevance of power strokes in molecular machinery is contentious as power strokes are often experimentally observed in biological molecular motors, but according to analysis based on kinetic asymmetry, the magnitude of the free energy released by such conformational changes does not affect the properties of chemically-driven molecular machines such as directionality and stopping force, and cannot improve the efficiency of a motor to work against an external force. To reconcile differing viewpoints as to the significance of power strokes in molecular machines, we attempted to use our framework to understand the ways in which a power stroke can affect a molecular motor while staying kinetically and thermodynamically consistent. Power strokes can be used to induce energy flow (equation ( )) and, in principle, could be added to the rotary motor by introducing attractive interactions between the barrier and the macrocycle (Fig. ), stabilizing distal co-conformers 1 D D and 1 H H , or by adding repulsive interactions between the free barrier site and the macrocycle (Fig. ), destabilizing proximal co-conformers 1 D H and 1 H D . Our simulations show that power strokes can change the magnitude of the current and efficiency of internal energy transduction (as defined in equations ( ) and ( ), respectively) despite kinetic asymmetry remaining unaltered (see Methods, SI section VI B4). This is because, while not altering K r , power strokes can still increase the value of Γ in equation ( ), reflecting their ability to favor forward cycles by inducing energy flow out of equlibrium (Fig. ). However, power strokes cannot drive directional motion in the absence of kinetic asymmetry (RT İ = -Ė when K r = 1), nor can they invert directionality while the kinetic asymmetry remains constant. In these simulations, altering power strokes and kinetic asymmetry together (SI section VI B5) gave the greatest simulated efficiency suggesting that modifying both aspects may be important for optimizing the design of synthetic molecular motors. We note that improvements that occur through power strokes arise from the induced energy flow rather than from any special role for the energetically downhill nature of the power stroke in determining the motor's behaviour. As our analysis shows, a prerequisite for the motor's operation is the availability of free energy to dissipate through mechanical motion. Therefore, any design feature that enhances free energy transduction from the chemical to the mechanical transitions could equally well foster improvements in performance.