I realize that I'm late on this one...
I had asked this question aeons ago and I wasn't satisfied with the response ... now that there is this overwhelming ovation I say this

1983 300D-T [142k] I consistantly get 24 dmpg {my rendition of diesel mpg} with A HEAVY FOOT ALL OF THE TIME

so there...

and thank all of you for loving your benz's and thank you for this site

Gregory
Connecticut
'86 911 turbo
'73 164E Volvo [250+k]