1978 240D 4-speed manual, non-AC, US model. Hwy 34.5 mpg

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Eric , are you still driving this car ? .

Back when I bought this car, 1982 240D Slushbox, it rarely got less than 27 MPG and easily got 30 ~ 32 on my long distance freeway jaunts, always fully loaded for those, drive to Nevada and back, AC on full, tootling along in the slow lane at 60 MPH .

A few times I got 34 MPG's coming back and once 36, I was well pleased .

In the last year or so it's dropped to 21 ~ 25/6 MPG and at nearly $5 / gallon I surely wish it was 27 ~ 30 .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

I use to have a euro model 240D, manual trans, this was a plane jane with rollup windows, no ac or cruise. I would get 33~34mpg average all the time with it.

When I had my manual transmission 240D, careful highway driving at 60 mph or so could see 29 or 30 mpg. Once I got 32 mpg, but the very next fillup, after driving same route at same speed in similar weather, only calculated out to 28mpg. Led me to strongly suspect the attendant had short filled me on the previous tank which gave a high mileage. Just another downside to our progressive Oregon law.

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John 5:25

1981 240D manual, 22 city with my kid driving a whopping 4 miles a day to school and back, about 27-28 highway when I take it somewhere. AC on most of the time.

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1981 240D Four on the floor, Orient Red over Parchment, bought with 154,000 but it's a daily driver and up to 180,000 miles, mostly original paint and all original interior.

I've tracked my 1979 240D over 7000+ miles since I bought it. In the winter it gets 18-20 mpg; in the summer, 20-22 mpg. A mix of about 75% stop-and-go driving and and 25% freeways at 70-80 mph.

Years ago there were posters that could not get more than 25mpg no matter how they drove. One poster Had even purchased his 240d new and claimed it had always been that way.

At the same time many got 30mpg or a little better. I never established the reason for this differential.

I do suspect that the poor quality of the diesel fuel sold in north America does cost about 5 miles per gallon. Compared to the diesel sold in Europe. At the same time our fuel is a lot cheaper than theirs.

Discrepency is best explained by some people are honest, others arent.

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We may have got cheated anyways. I think these engines might have gotten better fuel milage on European fuel Quality. Over the years to the best of my knowledge we have never gotten millage reports from European users. Is all diesel fuel sold in north America about the same quality in all regions?

For example we had a gulf station a brand that is gone now up here. We got really poor fuel millage on the product they sold. Usually in this region all diesel fuel no mater the brand was coming out of the same refinery. All us guys that were driving diesels at the time experienced this. The best millage was on the fuel that the refiner sold at their own Irving stations. This was also the refinery that supplied the other brands in our region.

I thought of driving habits etc for the claimed difference. I also went looking for any identifiable difference. I never really found anything.

We had a lot of response at the time for samples. What really seemed odd at the time was this pronounced spread of about five miles per gallon. There was nobody in that area. Now I see there are a few.

Another thing was I forgot then to get all the various model years that people where reporting on. They did change the cam at one point and claimed a six? horsepower gain.

Fuel usage wise it appears overall the turbo 5 cylinders are decent. More power with almost no penalty fuel consumption wise versus the better examples of the 4 cylinder owners.

Plus it takes some effort to get really accurate fuel millage results.

Mercedes developed the father of the last 616s way back in the late 1930s. There were changes but overall the last 616 to me was much the same.

We never saw much interest with the American car companies building any car diesels. Fuel was really cheap back then in north America. It was five American gallons for a dollar in much of my early driving experience. Or fill the tank for 4-5.00. I remember driving back and forth to work all week for a couple of dollars.

Hindsight is great as well. The old IDI volkswagon diesels did get better fuel milage on really hot days. I noticed this consistently. I wonder if the 616 does the same? It was pathetically hot the time we came out of Cleveland one summer. It seemed to us the old 240D was doing well on fuel consumption. After we got home I took it back into America after a time. In much cooler weather .

Not really cold though. I felt it was not doing as well for fuel milage. Just a seat of the pants kind of thing though. Logically you should get a little better overall fuel millage on synthetic engine oil. Enough to justify the additional cost is the question though.

Your mileage will be better if you only drive downhill.

I got 23/33 with mine but I drove it like it was on its deathbed. I never pushed it hard which is probably the most unhealthy way to treat those engines.

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84 300SD
85 380SE
83 528e
95 318ic

Thanx fellas ! .

I'm still not happy but at least I'm not alone in this .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

I got 30 mpg flat on a highway drive when I drove my '76 W115 240d 4 speed manual home after purchasing it, with a partially seized caliper, worn injector nozzles, worn front wheel bearings with long expired grease and cheap, wrong sized tires etc.

I'll report back now that most of these issues have been addressed.

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Why I will never do business with "DieselKraut" again

http://www.peachparts.com/shopforum/mercedes-benz-used-parts-sale-wanted/378935-why-i-will-never-do-business-dieselkraut-again.html

I eventually had to give up in attempting to find a specific issue on the millage issue between 240ds. I did not see the same issue on the five cylinder models.

Back then there was a gap where almost nobody was present in it. You either got 25mpg or less or you got 30 or more. This far more recent post shows some examples in the gap area now. These examples may be improved perhaps just with maintenance. As time moves along and we learn more about these engines. It could be worn delivery valves. Other than that one poster that said his 240d never could get more than 25mpg no matter what he did. From brand new. I always found concerning.

What I believe more than I doubt still. Is low fuel pressure to the injection pump creates heavier loading on the 616 engines number one rod bearing. It takes time for this to wear it excessively. Probably measured in years. How much do I believe this?

If I found the fuel pressure low on a 616 I purchased or owned. It is not that hard to plastigauge the first rod bearing. There were a lot of 616 engines that went to the junkyard with that issue.

Catch it early and the crank is probably not scored. They will run seeming okay with low fuel pressure. Yet will run enough stronger to feel it with good fuel pressure. The idle is also quieter and some members said they thought the engine was quieter on the highway as well.

How is this diagnosed and fixed? I suspect I may have low fuel pressure from my IP but have no way to be certain other than testing the IP timing (drip).

I've just had my injector nozzles and life pump rebuilt, so if this is an issue, the new injectors will likely make the cold starting issues I've faced (no start without slight throttle, smoke on startup) worse.

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Why I will never do business with "DieselKraut" again

http://www.peachparts.com/shopforum/mercedes-benz-used-parts-sale-wanted/378935-why-i-will-never-do-business-dieselkraut-again.html