Just curious what kind of mpg is normal on a well tuned 103.
THANKS!!!

I get about 25 per UK gallon (21 per US gallon) out of the M103 in my W126 and perhaps 1mpg less out of the twin-turbo M103 in my W124. My driving style is gentle to moderate, rarely fierce.

P.S. After multiple conversions from km to miles, and UK to US gallons:

M103 in the W124
Constant 75mph: 27.17mpg(UK), 22.55mpg(US)
Constant 56mph: 32.86mpg(UK), 27.27mpg(US)
City use: 21.25mpg(UK), 17.64mpg(US)

Source: MB Technical data passenger cars (October 1993)

I am getting 26 MPG (US), but drive mostly on the highways.
1989 300E. W124/M103

i get mid 20s in my 2.6 liter W124. mostly freeway

I used to be in the 20's, but now sit somewhere between the 15's and 18's