You know something? When it's on Auto, the A/C light is automatically turned on, activating the compressor, and when I turn that off, Auto shuts down. So basically if you are using the Auto feature in winter, it's giving hot air but it's also cooled with the compressor first. Quite a waste of fuel and energy. It does say in the manual that doing so will blow drier air by cooling the air w/ the compressor first, but A/C saps a bit of horsepower from the engine. So I never use Auto button at least in winter.