turbodieseldyke
Veteran Member
My 1998 A3 doesn't have a stock MFA, but I have an external unit (MPGuino) that grabs the Fuel Consumption signal from the ECU. After a one-tank calibration, and subsequent comparisons, I know that signal to be accurate within 1%.
Stock MFA's may not be able to be calibrated manually, like my MPGuino is, so I imagine the MFA -- and not the ECU -- is the source of the +/- 7%, 2-3 mpg errors that other people are seeing. I know I need to recalibrate mine if I change the IQ setting in VAGcom, or if I adjust the fuel pump; but once it's re-cal'd, it's good again.
Stock MFA's may not be able to be calibrated manually, like my MPGuino is, so I imagine the MFA -- and not the ECU -- is the source of the +/- 7%, 2-3 mpg errors that other people are seeing. I know I need to recalibrate mine if I change the IQ setting in VAGcom, or if I adjust the fuel pump; but once it's re-cal'd, it's good again.