I have a 96-M3 and according to the OBC, I only get around 18.5 mpg. On the highway, the OBC would indicated around 24-25 mpg. Does this sound right? I was under the impression that the car would 22-23 mpg in the city and high twenties on the highway? Can anyone help? Stuart M. 96-M3 PS: I only use 93 Octane - mostly Shell w/Amoco when possible