On my 13 X3, 28i took Delivery on May.
With 4150 miles, pure City Driving with ASS and Eco Pro activated at all times:
Always on half a tank,= less weight to lagggg around when climbing in uphills.
AC Off - with Eco Pro On
AC On - with Eco Pro On
Havent tried sport mode with Ac on, but i bet it would be worst, idk~
I Always fill up when the low gas light is On,
I spend around 25-30$ Half a tank, At 3.72-3.85$ a Gallon at the gas station in my town.