I have very rough idling when in extreme cold but only when in gear which makes me think it is transmission related. However my gas milage plummets from 18 city to around 13 in the extreme cold. Is there a relationship (sensor, feedback etc) between the outside air temp and fuel mixture/idle programming. I would if my gas/air ratio is changing because of faultly data given to the obc. just a thought. your thoughts appreciated.
04 325Xi, 74k