Mercedes-Benz Diesel automobiles were developed and produced for a different market, where the smell, noise and other idiosyncracies that make the motor unpopular in passenger vehicles for the masses in the US are overlooked when compared to the benefits of fuel economy (fuel cost in Germany in the 60's approached $1/gal), reliability (the original cars were engineered to be simple, no-frills machines) and longevity. Some of the features are strictly due to the Diesel combustion cycle, such as no ignition system making the machine simple, and the fact that per gallon of fuel, Diesel has more availble energy, contributing to its superior mileage under load, while the low idle speed and lack of throttling losses noted in an earlier thread, add to its fuel economy advantages while standing in city traffic.

Other aspects of the Mercedes-Benz Diesel, such as its reputation for reliability and longevity, are the result of purposeful engineering. The market Mercedes was cultivating in the 50's and 60's with the Diesel powered passenger vehicle was the taxi market. To dominate this market as Mercedes did through the 90's (the last time I visited was in 1997) throughout Europe, but most noticeably in Germany, Mercedes established reliability as well as maintainablity as primary design goals, along with operating economy.

The means to achieve the reliability were in some cases unique to the Diesel as the solutions were tied to the unique features of the combustion process (such as the fuel injection system). In other cases the entire Mercedes-Benz automobile line benefitted. Take the manual transmission clutch mechanism. Until recent years, there were no automatic transmission equipped Mercedes-Benz (or other brand autos) in taxi service in Europe. The fuel economy penalty was too great to justify the added intitial cost (automatics still cost extra on most cars in Europe). Consequently a highly reliable transmission and clutch were needed that could be operated by a normal human a few hundred times a day. The solution was a hydraulic mechanism. As a result, the MB clutch has been hydraulically operated for ages, but the original vehicles to benefit were the taxi cabs. When the design was fully developed for that market, Mercedes standardized all their clutch operating mechanisms on that, their most reliable design. This concept is called "best practices" in corporate lingo these days, but was a deliberate design practice at MB early on. The same is true for safety innovations - long lead by Mercedes-Benz - as they were developed they were applied across the entire range of vehicles. This practice has contributed to the overall reliability of the gas and Diesel automobiles produced by Mercedes-Benz over the years.

I have owned a series of Mercedes Diesels, from a 1971 220D and 1975 240D that are now retired to my currently operating 1982 240D and 1991 350SD. Each of the 220D through 240D models has been unusually reliable, logging over 240,000 miles and only retiring due to corrosion of the body (Northeast affliction). The last one is probably going to be retired near 300,000 miles due to wear on the engine (it is getting hard to start) and rust. The 350SD is another matter. I had the engine rebuilt at 162,000 miles due to increased oil consumption that was traced to cylinder wear resulting from BENT CONNECTING RODS. I am still unable to figure out how the connecting rods on two pistons were bent, but this vehicle has been an order of magnitude less robust and reliable than the 220D and 240D's.

I also own a 1986 190E 2.3-16 that I imported from Germany in late 1985. I have driven the car 197,000 miles and it has been mechanically rock solid (new rear shocks and valve seals installed 80,000 miles ago were the only major repairs it has needed to date). While I do not think it will outlast my 240D or be as driveable in its old age as a Diesel, this car has convinced me Mercedes-Benz cars are uniquely reliable, with Diesels being the "proving ground" for technical features that add to overall reliability. Jim

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Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Gas is about $5 a gallon in Europe now. Diesel is a little less, but as pointed out in this thread, there is more energy per volume in diesel than in gasoline.

I was in Switzerland in April. I had a unique vantage point one afternoon in the office where I had been working. I stood at the window at about 5:00PM when everyone was driving home from work. There was a buisy two lane road outside the third story window I was standing at. Many of the cars were slowing down or stopping to find a gap in the oncoming traffic and make a left turn. Almost every single car I saw, changed gears (were manual transmissions) when making the turn or speeding up after the car in front of them turned.

The people in Europe, by necessity have not succumbed the laziness level of the typical American and found that they can no longer shift for themselves.

A properly designed diesel will outlast an equivalent gas engine under any driving conditions if driven and maintained properly.

Have a great day,

My uncalled for 2c worth. It would seem that this debate is not an “either - or” matter. Diesels last longer for both the engineering aspects as well as (hopefully) the type of person that owns them. (Warning, redundancies forthcoming)

The engines are built ruggedly to survive the inherent stresses placed upon a diesel combustion process. The slower engine speeds are a factor as well – the rate of wear vs. RPM is a logarithmic relationship.

The owners are usually people that are relatively easier on their cars, not someone looking for 12-second quarter miles. They are not going to beat the hell out of an engine, they are more likely to be looking at fuel mileage as a goal - not beating the guy in the other lane to the next stoplight.

They are (again, hopefully) more dedicated to maintaining their vehicle properly. This makes all the difference in the world. When people mention their desire to own a Roll Royce, for example, I tell them that they (the Rolls, not the person ) are the most lovingly hand crafted P.O.S. ever made. I tell them that if someone bought a Ford Pinto when it was new, and then proceeded to lavish upon it the care & nurturing that a Rolls receives, it will last just as long. (Actually longer, but I don’t usually want to upset them *that* much )

Thanks for the opportunity to rant & ramble.
RTH

would like to look at this thread 300 years from now.........
William Rogers.......
74 240D
81 Sd
81 Chivy hot rod Blazer