Ah feeling the love. yes I am a professor and am very capable of doing the math. I have not yet done the math manually for the x5's mpg. I was just going off the OBC. I have had it for about a month and a half. I thought it sounded high. My xc90's OBC was dead on so I thought this would be pretty darn close. I got the 27.xx twice over a 300 mile highway trip. After I made the trip I thought that I would check it again so I rest it and got the just about the same results. I reset it again when I knew I would be doing a lot of mixed driving and got an avg. of about 22.

I will have to fill up and do the math manually next time to see what it is. I guess my mpg bubble will burst.

PS. living in the land of chocolate is awesome