OK . . . back to OP's question:

I owned:

'84 190D, 5-spd, 2.2L engine - 37 mpg, religiously, would have gotten 39 - 40, but had wide tires, low profile (sniff, sniff . . . my beloved Gretta got bent frame from 15-yr old driving suburban after 6-yrs trouble-free driving - just had done valve job, new clutch when crashed)

'76 240D, 4-spd, 2.4L engine, 33 mpg in high altitude, peppy like gasser, Pierre bought and says gets 36 MPG around Miami

'83 300D, 26 -28 mpg w/o air . . . lose about 2 mpg when A/C working - hmmmm, gonna have to look at the 3:07 more carefully . . . I hate my mileage to the point considering trading for a 4-spd 240D in equal condition. The 300D has about 200K on it (odometer quit working about 3K miles ago).

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1983 300D, the "Avocado"
1976 240D, 4-spd the "Pumpkin", SOLD to Pierre
1984 190D, 2.2L, 5-spd, my intro to MBZ diesels, crashed into in 2002