A couple thoughts:

1) did you use the hidden menu test 21 to reset your mpg?
2) have you looked at the mpg calibration in test 20?

You need to determine actual vs indicated mpg/range and determine if your computer is reading wrong or the car is actually consuming much more fuel.

I would probably preemptively strike on the reset mpg calculation in test 21 then see if it goes back to normal. It seems test 20 is for calibrating the fuel consumption of it's inaccurate.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)