My Aircon uses about 4kw (3 to 4 is typical) plus several 100s W for the fan. So ev usage time times that is the reduced power available and thus reduced range. It is just as noticeable on a petrol car especially on lower power compact versions, it won't have too much impact on gas guzzling engines since they are already inefficient and usually more powerful so it is less noticeable, though the added consumption will be more of course.