220D mpg and oil consumption

I've got a '71 220D that I'm using for my winter car. It's a great car and starts with just 30 second glow down to about 10F then I have to plug it in.
Pick-up on this car is fairly decent and I have no problems merging on the interstate and cruise around 75mph.
The original miles on my 220D are anyones guess, but on paper it looks to be about 120K.
My question: I'm getting only 23 miles per gallon (mix highway and town) My oil consumption is about a quart every 300, 350, 400 miles. Does this seem normal?
The owners manual says consumption should be about pint every 200 miles.
My 300 SDL with 320K miles on it barely burns a quart before oil changes (4-5K miles).
Thanks for your response
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Normal? These engines normally use NO OIL between 3,000 mile changes at least for the first 300,000 miles. MPG should be 25 city, 33 highway.
Bill Ditmire Ditmire Motorworks,Inc. 425 White Horse Pike Absecon,NJ 08201 http://www.ditmire.com 609-641-3392
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A different tack completely, but most impressed with my '01 C200K - not a drop of oil needed between 13,000 mile service intervals up to 97K. My first car ever to do this.
Neil UK

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Thanks all, but wouldn't the exceptional acelleration (better than my previous and newer 240D) and postive cold morning starts preclude a worn engine/oil rings?
This morning for example, the temperature was 8 degrees F and after a 30 second glow, the 220D started on the first pull.

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A 30 second glow? Good grief, it should've started without a pull.
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James I sympathise. I have exactly the same problem with a low mileage 1982 240d. Mine too performs very well which does seem to make a worn engine (i.e. low compression) unlikely. I think it is more likely that we may have a problem related to the low mileage our diesels have covered. What i am getting at here is the problem of carbon build up in under-used diesel engines. This can clog the piston rings causing them to stick and not control or prevent the passing of oil into the combustion chambers. You won't see any exhaust smoke because a diesel engine will happily and cleanly burn off the engine oil. The solution, i am told, is to drive the car hard over many miles ("The Italian Tuneup") and may be consider changing to synthetic oils which are said to help shift carbon out of the way. if you do a web search around Italian Tuneups for diesels you will get all the info you need. It is supposed to take many, many miles - i am still waiting for any significant improvement after 5,000 miles of such driving. Let me know if you come up with any other possible ideas as to what could be wrong with our engines.
Cheers
Pete
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James I sympathise. I have exactly the same problem with a low mileage 1982 240d. Mine too performs very well which does seem to make a worn engine (i.e. low compression) unlikely. I think it is more likely that we may have a problem related to the low mileage our diesels have covered. What i am getting at here is the problem of carbon build up in under-used diesel engines. This can clog the piston rings causing them to stick and not control or prevent the passing of oil into the combustion chambers. You won't see any exhaust smoke because a diesel engine will happily and cleanly burn off the engine oil. The solution, i am told, is to drive the car hard over many miles ("The Italian Tuneup") and may be consider changing to synthetic oils which are said to help shift carbon out of the way. if you do a web search around Italian Tuneups for diesels you will get all the info you need. It is supposed to take many, many miles - i am still waiting for any significant improvement after 5,000 miles of such driving. Let me know if you come up with any other possible ideas as to what could be wrong with our engines.
Cheers
Pete
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