Over 1.5 years of ownership and 18,000 miles, the average for my '84 300td is 27.6 MPG, with a low of 23.7 MPG on the way home from buying it, and a high of 30.1 MPG during the 100F+ days we had in Atlanta last summer. About 2/3 of my driving is in traffic, averaging 35 MPH.