I'm just curious how long it took some of you guys to "break-in" the engine and start getting mileage near (or over) the EPA rated 27/37. I took my car on a trip from Portland to Tacoma, about 300 miles of 99% highway. I stayed between 65mph and 75mph the whole time, used cruise and kept a very light foot (i've always been able to beat the EPA numbers in every car I've owned). At the end of the trip, I only had an indicated 31mpg My car had 450 miles on it by the time I was done, so I'm wondering how long these engines stay "green". 31mpg is much better than my old 525i, but I was expecting closer to 40 [???] Thanks!