Abstract: A means and method for reducing and/or eliminating the drag and power loss imposed on a vehicle engine by air conditioning that is driven thereby, during selected load and power demand situations, both to conserve and have added power available and to provide improved fuel economy, and which includes; a vacuum responsive switching device provided in the electrical line operative of the air compressor clutch, means for readily adjusting the responsiveness of said switch to different and varying load conditions, and use of a fast idle connection that is inoperative when the air conditioner compressor is cut-out and also inoperative.