good days are coming, it happens to me also about mileage on my honda city 2009, in this HOT SUMMER in peshawar/nowshera one cant dare to turn off the ac, my city was giving me mileage of 16-17kml with full ac, after that pleasant weather i drove my city to peshawar twice, which is 32km one side, mean 128km all, without ac, so it was giving me mileag of 20.5km, it also amazed me, but after that pleasant days gone and hot wether is back here, so mileage is back like 17km..
due to buying a car for relative iwas also travelling to isb , yesterday and today also, never knew you were there..