Prior to the arrival of the MB 300D, and the soon-to-come VW diesel, oil burning passenger cars required substantial sacrifices, most of all in performance, along with noise and vibration. A MB 240D took some 28 seconds to, ah, slowly increase its speed from rest to 60 mph. Mercedes rightly saw a problem: there was no obvious way to upsell traditional MB diesel buyers, since they tended to be diesel die-hards. And Mercedes also wanted to increase the attractiveness of their diesels to potential (gas) six cylinder customers, especially since the gas six was losing performance due to emission changes. The solution was rather brilliant: add another cylinder to the 240D engine, make some other changes to improve its smoothness and driveability, and launch the first mass-produced 5 cylinder “motorcar”. Astonishing indeed.
As the article makes clear, there were more changes than just adding a cylinder. The 300D was the first Mercedes diesel to use a new governor system to control the diesel injection pump, which improved response to the accelerator pedal. And due to careful balancing and special motor mounts, it was deemed to be closer to the six in its vibrations than the four. Mercedes’ success with their five was soon followed by Audi doing the same thing with their engines. The Germans had found a solution to satisfying the power-hungry Amerikaner by adding one more cylinder.
Of course, objective performance was still leisurely; 0-60 in 20 seconds. But in normal daily driving, that wasn’t really all that bad. The 300D would keep up with traffic quite nicely, and once up to speed, did very well on the highway. R&T got theirs up to a whopping 98 mph!
One of the engineers at KSCI bought one of these, and I remember being pretty impressed in one or two rides with him. It was clearly smoother and more powerful than the 240D, which I had exposure to. And of course, all of its other very outstanding qualities in therms of ride, handling, brakes, and feeling of profound solidity were all just accentuated by the new 5 cylinder diesel. The 300D was a significant breakthrough vehicle for MBZ, until the even much better turbocharged 5 cylinder came along. Then suddenly the normally aspirated 300D felt just like a slug in comparison.
I still miss my ’82 300SD. With the turbo it only felt slow when going up on ramps, and for the era it was probably faster than average. The theoretical increase in vibrations over a four cylinder aren’t a big deal for a diesel which is already so much more intrusive than a gasoline engine.
As a side note, Lancia was again one of the first to develop a 5-cylinder diesel, even if it was used in a military truck, the 1938 3Ro. It was quite an advanced engine : aluminum block, 4 valves per cylinder, direct injection…
Gardner had 4,5,6 8, cyl LWs.The lw arrived in 32 an automotive legend.
I always liked these. These days folks think you are risking your life in a 10 second 0 to 60 Prius, but people got along fine in these and I survived driving a Peugeot 504 diesel in the 90’s as well. I suppose it never occurred to them to make up for speed with paying attention and strategy. . . Try driving a real truck (not a wanker brodozer) with 40,000 lbs in the box and this car becomes fast. The aforementioned Prius becomes the space ship it actually is.
It was genius for MB to feature diesels in the standard sedans in the USA. There was no way that the gas offerings were going to match up to the responsiveness, power reserve, and quiet of a high end domestic compact with their small block V8s. So being able to have a diesel that delivers economy beyond anything in the size class gave a great selling point for those of a certain mindset.
i’ve got one 35k mi gonna sell in 12 mos
any recommendations?
My wife’s family were huge Mercedes fanatics, and they especially loved the diesels. Her uncle had a 1976 300D which saw hard use for years before it became my then girlfriend/now wife’s first car in 1988, with about 250,000 miles on the odometer. She drove it for another 3 years, and it certainly embodied the strengths and weaknesses of MB diesels.
One the plus side, the car was incredibly well made. I couldn’t believe a car that old, with that many miles, could still feel so unbelievably solid. The MB Tex upholstery was basically like new (that stuff was indestructible) and the quality of manufacture and materials was beyond impressive.
But, for the negatives, the 5-cylinder diesel was engine was noisy, smelly and slow. For normal commuting it was a slug, and could barely move away from stoplights. If you floored it, the car emitted a burst of black smoke that would have been appropriate in a James Bond film. It was embarrassing to say the least. The smell was horrible too–the whole car had the subtle reek of diesel fuel. We actually avoided driving it on the highway because merging was terrifying and dangerous. Yes, the car was fine at speed, but getting up to speed was another matter.
All that said, we still have fond memories of the car. It really was such a functional, solid machine–a Mercedes-Benz in the best tradition. But if we had a do over, there’s no question we’d go for the gas powered 280.
GN you not knowing how to drive a diesel is hardly the cars fault. I had a Toyota Corona N/A diesel automatic that never had problems in town traffic it was listed as a delivery van by Toyota not a passenger car so its primary role was city traffic driving, slow? certainly but no slower than most traffic, revving the crap out of a diesel is not how you speed the car up shifting into a higher gear and making the engine pull works every time.
Both my wife and I were quite adept at driving the diesel. The fact was the car was frustrating to drive in urban cut-and-thrust traffic, and it was unacceptable merging onto fast moving, heavy interstate traffic, especially entrances with short on-ramps. MB clearly understood that many American drivers would find even the 300D too slow, and therefore they soon added the turbo, which made a huge difference. My mother-in-law had a turbocharged 300SD for decades, and it was a far better experience. Same Mercedes high quality and diesel longevity, far better performance for day-to-day driving with typical American road conditions.
i was a 240d 4 spd manual owner and quite adept at driving it. that being said, if i were ever to go mb diesel again, i would be looking for one of the turbo-diesel models. it’s no fun being stuck on a hill with a car full of people doing a handbrake start while blue fog pours out the back. my only knit with the 300d was why didn’t they offer it and the later diesels with a manual transmission? i bet you could get a stick in europe!
I have an ’84 Euro 300TD, with manual heat-AC, manual windows and a factory 5-speed stick-shift. It don’t need no stinkin’ turbo!
Happy Motoring, Mark
That sounds a lot like the folks who drive some clapped out jaloppy talk about how it’s actually just fine-if you just know to turn the a/c off and dim the lights when you are going to merge so it doesn’t stall but let off the gas a bit when you get there to make it shift.
Ok, sure, but I’d rather just have a car that I don’t have to worry about if some jackass comes up quick on me.
And can’t remember which magazine or even which year it was published, but one had a article (I think it was Special Interest Autos) on a experimental Ford inline 5 ‘ol Henry had his engineers design back in the 30’s. Their problem then was designing a proper ignition system for the thing. But one of the fella’s ( who was still living at the time of the article) who participated in the road test did say they had a lot of fun with gas station attendents and mechanics with it.
I think I read that article. The guy said that when a pump jockey told him he had 5 cylinders, he’d say, deadpan, “Don’t tell me that–I paid for 6!”
Yup, that’s the article. I remember that quote.
Sweet looking Mercedes-Benz. I’ve always liked these old-school diesel engines.
Any older Mercedes Diesel that emits clouds of black smoke at any time, are in serious need of routine service .
I’ve owned several naturally aspirated Mercedes Diesels including two 5 cylinder W123’s and they never smoked .
Slow yes but no worse than the average small car at the time .
-Nate
I have to agree. One thing I like about Mercedes-Benz Diesels is that they’re better looking than the VW Golf (Rabbit) Diesel of the same time period. I also like how well they’re built. Although I’ve never owned or driven a Mercedes-Benz Diesel car, I’ve ridden in plenty over the years, and I find them more comfortable than the VW Golf.
I would hope a Benz would be more comfortable than a VW, sheesh…
They certainly were beautiful and built like a tank. OTOH they cost 2-3 times what the Golf did, so I would hope the engineering and build quality were better.
I’ve never owned a Mercedes-Benz, so I wouldn’t know.
Just about any non-turbo diesel will smoke if punched from a stop. Even the turbo 300 diesels are slow…the automatic 240D is glacial.
(!) Around Bekeley CA, these old boats have become the darlings of the eco biodiesel crowd. It is remarkable how many of them are still seen clattering around the streets there 40 years on.
Can’t these things also use old (well-strained) cooking oils to run as well as diesel? This is classic MB territory – I even like the big bumpers!
Ditto a few miles south in Santa Cruz. A few are used as taxis. Honestly, though I can hear them, usually smell them, and occasionally see their exhaust, I can’t say they hold up traffic.
There are quite a few still alive in Richmond as well. The W123 is far more ubiquitous, but these are among the cars that the bulletproof legend was built on.
First of many Mercedes in my family. It was followed in fairly rapid succession by a 1978 230 gas, a 1979 300TD wagon, a 1981 300TD turbo wagon and a 1982 300D turbo sedan. I wasn’t old enough to drive any of them so have to go from what my parents said at the time. My dad never complained of the performance of the 1975 300D. He called the 1978 230 (gas, carbureted) the most gutless car he’d ever owned. Mom liked the 1979 300TD (naturally aspirated) better than her later turbo wagon as apparently the gearing was lower and the auto started in first gear. For years I thought she was crazy to say the the naturally aspirated car was faster. I couldn’t see how it was possible. Later I learned that in order to enable a very high top speed of 125 in the 300SD, Mercedes had changed the gears to much taller ratios, and at the same time to smooth tip in, had structured the transmission for a second gear start for all but full throttle starts. The result around town was turbo lag compounded by high gearing unless you knew to step fully into the gas.
Incidentally, Mercedes stuck with this approach for a long time as my 1993 300E also had a second gear start. Even with 217hp, it required a heavy foot and a touch of planning to achieve a fast start.
Wow. 20 seconds 0-60. You can’t even buy a car that slow anymore. Simply doesn’t exist.
1975 was 41 years ago. Go back 41 years from 1975 and it was 1934. What improvements in car performance comes with four decades of development. Granted, MB diesels were a special (slow) case, but many of us were driving ten+ year old 40hp (SAE gross) VW’s in 1975.
1930’s V8 Fords were good for 0-60 in 15-16 seconds. A 6 cylinder Hudson Terraplane could do it in 13.5-14 (per a period road test). In 1960 one of the car magazines compared a Model A to a new 144 cube Falcon. The Model A did 0-60 in 27 seconds and topped out at 68 mph. The Falcon did the same run in 21 seconds and topped out at 72 mph (I think thats what I remember). However the big dog of the 30’s, the Duesenberg in sedan form with the supercharged 8 ( and weighing 6500 lbs!) did 0-60 in 8.5 seconds and topped out at 109mph. The Roadster took 8 seconds to 60 and topped out at 116 mph. It only weighed 5900 lbs.
been driving a citroen 2cv for 14 years when we bought our 300 turbowagon. Wow, what a power we thought.
That is 11 years ago and we still drive both. The 2cv has about 30 hp and weighs 1500 pounds, the wagon 125 hp. and almost triples the weight.
Both are fine in town but highway travel is easier with the Mercedes, no slug at all and traffic in the Netherlands is very aggressive! (done both)
It is all relative… speed.
20 sec 0-60 may be slow today, but almost 1/3 faster than the 240D. And the difference between 28 seconds and 20 seconds probably feels like a small eternity!
Love the old International Transtar behind it in the photo. Interesting setup though–it appears to be a box truck of some length, with a full-length trailer attached? I suppose such things were legislated out of existence at some point, or perhaps never allowed on the east coast in the first place. Double short trailers used to be common here, and now they’ve all but disappeared, and I remember reading that Texas and the great plains used to allow triples…
Tollways in the northeast allow double 48′ trailers!
1975 300D 40,000MI.
excellent condition
any offers?