MPG woes with 1970 220d with automatic tranny

[Alan Hershman]

I recently purchased a 1972 220d with automatic transmission. The seller swears up and down that the car made 35 mpg on average. I am getting only 25 mpg now. I have recently had work done including new timing chain, chanin tensioner and valves adjusted. The engine has about 80k on it and the tranny has about 8k on it. The car does not smoke hardly at all. People in the know tell me it sounds great, including a 30plus year mb mechanic who worked on it. What might be causing the low mpg? Half the reason I bought this old thing was for the good mpg in such a sturdy rig.

[thorsen]

Let's assume that the seller really did get 35mpg - what conditions did he get that in? In other words, was he driving 45 mph and you are driving 65mph?

I think 35mpg for that vehicle is optimistic.....

[Zeppo2K2]

Hi Alan,

I think you are getting the correct mpg, but it really depends on your driving. I just purchased a '71 220D last March, and put on about 10K miles, getting 30mpg overall. It has a manual trans. In the mid 70's I owned a 240D for 40K miles, and it got 28mpg overall. It was manual trans. I recorded all fuel input for the entire period of driving for these numbers. My driving mix has always been about 30% urban street driving, and the rest freeway speeds - 65-70. This is true for each of the cars.

I find it difficult to believe one could get over 30mpg for any of the 220 or 240 M-B diesels with normal driving, as these are large cars for that tiny engine.

But then I have friends who get 50-60mpg out of new hybrids. They do so by crawling up hills, losing speed as they go to the top, and coasting down the other side, much to the dismay of following drivers. Not really normal driving.

Ron

[Mike D]

25 MPG is pretty normal mileage for a 220D. I drove one for 8 years and that is what I averaged. Freeway mileage is not going to increase very much with the smaller engines. At 60 MPH they do pretty good but once you get up past the diesel's torque range you're just spinning the crank without producing any horses.

Going to larger tires will help freeway mileage but it drags the car down in town.

What's wrong with 25 mpg in a 37 year old 3600 lb car?

[Skippy]

25 sounds normal to me. See this thread: Fuel MPG poll

[t walgamuth]

There is simply no frikking way he got 35. YOu are getting as good or better than you can expect in an automatic car.

Tom W

[Lycoming-8]

Our 1968 220D was a daily driver for nearly 20 years from 1970 to ~1990. During that time the general routine was 20miles a day to work and back in a somewhat rural city. However in those years stoplites were set so that most of the time you could pretty well time your way across town. The car had a stick and yielded an almost unwavering 28mpg. On the many hiway trips it saw, doing probably max of 62 - 63 mph, it yielded around 33mpg. On one run south from Amarillo to Lubbock with a tremendous tail wind we got 42mpg. At today's speeds I'm sure the mileage would not be in the 30's!! And remember this was a stickshift.

[nhdoc]

Your seller was smoking crack or didn't know how to divide if he though he would routinely get 35 MPG on an auto tranny 220D. 25 is more or less normal.

When I bought my E300 the seller said "gets 37 MPG - nearly 800 miles on a single tank", yeah, well, on my drive home from Philadelphia I saw mid to high 20s and for the first year I owned it I never broke 30. Only once have I ever seen close to 37, I once got 36 when I drove the speed limit all the way to NJ and back, 500 miles all highway at 65 with no A/C. Yeah, so it is possible that once he got 37 with it...but to sell it with a statement like that is pure hype.

Put your car in perspective. In 1970 the average detroit crapbucket was lucky to see 15 MPG and most were great big V8s getting 8-12. 25 MPG back then was revolutionary for a sedan. Not that it is any consolation to you if you bought it expecting to see 35 - I'm afraid that's not going to happen.

[Kpmurphy]

Do you have any pictures of the car?
I drive a 1970 220D
The odometer is broke on my car so I have no clue how many miles I get per gallon.
Does the car run good and plenty of power for a 220D?
I do think you can get better fuel mileage out of a standard, but nobody can shift faster than our automatics, I think the automatics are faster 0 to 60.
Kevin

[Mike D]

220D automatic FASTER? I dunno, I don't think I used THAT word ever with my 220D's

[t walgamuth]

NO frikkin way an automatic is faster.

It is true on a car with a very large powerful engine but not on the low powered car like a 220d. The automatic sucks too much horsepower!

Tom W

[Kpmurphy]

I have always driven standards. And I have always argued with my dad about automatics and standards. I always thought that there is no way an automatic can shift faster than you or I. Now that I have an automatic there’s no way I could shift that fast. So I learned something today It is true on a car with a very large powerful engine but not on the low powered car like a 220D. Just for the fun of it I would love to get these old Mercedes in a drag race, 240D and a 220D auto or standard
Kevin

[t walgamuth]

Originally Posted by Kpmurphy

I have always driven standards. And I have always argued with my dad about automatics and standards. I always thought that there is no way an automatic can shift faster than you or I. Now that I have an automatic there’s no way I could shift that fast. So I learned something today It is true on a car with a very large powerful engine but not on the low powered car like a 220D. Just for the fun of it I would love to get these old Mercedes in a drag race, 240D and a 220D auto or standard
Kevin

The key is not the speed of the shift in this case which is undeniably faster with the automatic. The horsepower sucked by the automatic is (I will guess) ten horsepower. If you have 500 hp that is insignificant. If you hapen to have 58 as in a 220 (or so) it is a lot.

I think the newer electronically controlled trannys probably do not suck so much power and probably are quicker even in a low powered car. In fact they feel as if they use clutches and are controlled by solinoids. So the power loss should be minimal.

Tom W

[todds]

Yeah, our POS saab, which is a 2005 2-liter model, has a manu-matic shifter. This is basically an automatic transmission that holds gears (more or less) when the shifter is in a certain position. If I force the thing to stay in third, it's really interesting: The revs will rise with the speed of the car, as expected, until about 25-30 mph or so and then the tach drops a good 500 to 1000 rpms, then it rises again as usual. You can feel the lull in the motor at this point as well. I assume this is the "torque converter lockup" feature most autos have had since the 80's to save gas. It basically eliminates the torque converter from the equation and connects the engine directly to the wheels. I had an 83 Olds wagon with one of these that failed and it would jutter and stall out at idle, like a manual car with the clutch engaged. I didn't notice the lockup with that car as much as with the new car, it's a really dramatic difference in the engine.

All that said, the manual 05 saab's are STILL rated higher for MPG than the autos, as are most cars across the board and all mercedes. The only time a manual is rated lower is when it accompanies a different or differently tuned engine.