ive currently got a 18 button OBC in my 318is, i presume its not a standard item inside the car so what is the accuracy likely to be like? since getting the car the most MPG ive had is about 28 and thats driving as carefully as i can. also i notice the range drops in like 3's or 5's which is a concern when your nearing the red light. also my temp sensor is playing up or bust as read its always -37*c which obviously is wrong.
so yeah just wondering why my mpg is so shite, is it because the car perhaps needs a good service or is the OBC playing up?
thanks in advance guys