Well.. Depends on whether we're talking about the OBC display or calculated based on miles and fuel fills.. The OBC usually over-predicts by 2-3 mpg.. Calculated, I used to get around 21-22 mpg city, 30-31 mpg hwy and around 23-24 mixed... A little more in the summer, a little less in the winter. '04 325i with 5-speed manual and around 80k..
E92 convert. BMW Fanatic.