Off-Piste S4

I need some help identifying the correct Measuring Block Group under Instruments to tweak the trip computer calculation for mpg for my 2004 allroad. Mine consistently records ~2 mpg higher than I am actually getting. I have searched and found instructions for the B6 platform, but this isn't accurate for the allroad. I have found that Group 11 under 17-Instruments has a value (100%) for the "miles remaining" but don't know if this is the correct value to change.