I had the M calibration last week.

Prior to this I never had any flashes. My 8 was purchased on 1/28/04.

Average MPG was 14.5 mpg with my auto.

First tank after M = 16.0 mpg, but that was 50-50 city/highway driving.
Second tank (half fill) after M = 13.38 mpg, all city driving.

I was *hoping* the M calibration might help my fuel mileage but I guess it hasn’t.

My question is:

Is it possible to have gotten the M calibration without getting any prior updates? Or does the M calibration include all prior updates?

I don’t know WTF to do. My fuel mileage is horrible and I am NOT driving like a mad man. I just don’t get it.

(I tried searching but sometimes I wish members would be specific in their subject as to the contents of the post; I couldn't find anything to answer my question.)

 

M includes all prior updates.

 

it's backward compatible.

 

???

 

backward compatible = includes all prior updates/changes.

Your mileage should improve as you put more miles on. With almost 10,000 on mine, I get 17-19 around town, and 22-25 on the highway.