Like any rotating motor? An air-conditioning compressor does take away from overall performance. Heating is also an issue to cold climate usage. They are saying a 20% reduction to accommodate heating in winter months.
Winter months are not advantageous for any ground travels. My Cummins diesel hates cold air. Loves the heat. (However, once warmed? My 440 loves the winter air. Very low humidity and slightly higher oxygen density?) Umm umm good. Just can't expose the car to the road salts.