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How bad is Mercedes reliability, really?

5342 Views 66 Replies 13 Participants Last post by  ccmbduong
I've heard so many horror stories about Mercedes reliability, and CR has of course not been kind.

But how large is the difference between Mercedes and competing vehicles, really?

I suspect that the difference, on average, is less than many people think. There's not much distance between CR's dots--about 0.03 problems per car for a 2006 model--and forums like this one make problems seem much more common than they actually are.

In late 2005 I started conducting my own reliability research. I'm reporting absolute stats like "times in the shop" that will make the differences between cars much clearer. Relative ratings obscure too much--how large is the difference between "better than average" and "worse than average"? I’ll also be updating results four times a year, so there will be information on new models sooner.

I'd like to provide this information on Mercedes models, but so far too few owners have signed up. I have far more owners for competing makes.

To encourage participation, panel members will receive full access to the results free of charge.

Details: Vehicle reliability research

Comments, questions, and suggestions welcome.
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If you're seriously looking for an answer to your question--and not just trying to start trouble--do a SEARCH! There are thousands of posts on the subject.
mkaresh said:
Did you read more than the title?

I'm trying to provide some real information, so people can stop starting so many inconclusive threads on the subject.

Good sig.
Well, I'm sure we are all indebted to you, but why don't you just do a search? It's no accident that no one is jumping into this thread. I am just trying to do you a favor too...
asianml said:
Try visiting his website. A post search won't do him any good. He wants Mercedes owners to sign up on his site and personally enter info on his site so he can gather this information for us. Think of it as on a smaller more personal scale.
He could fill his site many times over w/ a search of just my past posts on the subject, if he really wanted to. He should have at least started w/ a search and said so.
asianml said:
Have you looked over his site yet? The point of it is for you to enter the data yourself on there.
That is lazy x2. He's too lazy to do a search and too lazy to enter the information himself. Don't you wish you could go through school that way? Just let other people do your homework for you!
asianml said:
You didn't visit the website, did you? It's your car, you enter the information. Simple as that. He can't possibly know every single detail about your car, but you do! Many posts don't tell the whole story, mostly a shortened version for easier understanding and easier reading, so he wouldn't be getting the whole thing most of the time. His site also does surveys, which he certainly can't do on your behalf.
He should have you do them for him...
mkaresh said:
I'm sorry for all the confusion.

This is real research. The goal is to be able to say, "The average Mercedes X-Class requires about 1.2 repair trips per year, while the average Competitor Y requires 0.9 repair trips per year. So the Mercedes requires about one extra repair trip every three years." People can then more easily decide if the advantages of the Mercedes outweigh this disadvantage.

Right now, there's no way to make such a clear comparison. As a result, it's very possible that people overestimate how many repairs they'll have with a Mercedes. Everyone is of course aware of CR's take on Mercedes reliability. What few people realize is that the differences between CR's dots for a 2006 model year car is about 0.03 problems per car. That's about one extra problem for every 30 cars.

For the results of my research to be valid, it's as important to know how many cars have not had problems as how many cars have. The problem with gauging reliability from forums is that there's no way to tell how many cars are not having problems. Also, people with problems are much more likely to post here.

To provide the most valid possible results, my research process only collects data on repairs that haven't happened yet (with the exception of the first month). So people sign up, and afterwards report repairs when they happen.

If there are no repairs, participants simply provide an approximate odometer reading at the end of every quarter. That's how I know the total number of cars to include in the analysis.

Currently over 11,000 people have joined, with over 14,000 cars. The problem is that only a few hundred of these are Mercedes.

As stated in the OP, everyone who helps out will get full access to the results for free.
Thanks for the additional info on your research methodology. It alleviates a few of my concerns, but by no means makes me believe your results will be valid, in the way you think they will. You are correct in noting that "people with problems are much more likely to post here," so your sample-selection procedure begins w/ a negative bias built in. And the idea that only reporting on "new problems" will somehow improve reporting reliability is just plain wrong. I don't believe that anyone who is satisfied or completely satisfied w/ their automobiles will ever take the time or trouble to get involved in "research" like this. You will primarily attract people who are angry and/or people w/ agendas of one sort or another. I have seen CR's methodology and it is not only flawed but biased against certain cars. I believe your results will be even more subject to collection and reporting problems than is theirs.

I have neither the time nor the inclination to trouble-shoot your methodology here, but I have grave concerns about what you are doing and question why you are doing it. I am a research scientist and have seen too many of these well-intentioned (I'm assuming your motivation is honest and sincere) studies used and misused by naive people and those w/ agendas, and I see no controls in yours that gives me confidence this will not happen here.

I admit I have not spent a lot of time on your site, but I am curious about a couple of things: Who is sponsoring your "research?" What exactly do you plan to do w/ the data? What are your credentials for designing and conducting this research?
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mkaresh said:
Credentials: Ph.D. in sociology from University of Chicago, which includes a lot of training in survey research; while there spent five years working at the National Opinion Research Center, a leader in the field.

Your concerns:

Most people who participate consistently participate, whether or not they've had problems.

Unless people check in at the end of the quarter, their responses earlier in the quarter are excluded from the analysis.

When people have gaps in their responses, I follow-up to fill the gaps. This affects only a couple dozen of the couple thousand people who've been responding, about one percent. Only 20-30% of participants report any problems in their first six months of participation.

Your concerns make sense, but the actual data demonstrate that they aren't actually problems.


Not much right now. Eventually there will be two ways to gain access to the results: participate in the research or pay a membership fee. Right now only the first is available. I feel this is a very fair way to structure the research, since those who want others to do all the work will enable those who do the work to get the results for free. With CR, you pay just as much even if you take the time to fill out their surveys.
Thanks for that info! It helps to some extent, but as you probably know better than I, survey research is notoriously unreliable. But I wish you well anyway, and hope you are very successful and make lots of money! We social scientists don't do either very often.

And I won't be participating since I have had no problems to speak of w/ my automobile.
asianml said:
I'm in!!

Jayhawk, you said you aren't joining because the S has had no problems. Well there's a reason to join!! Gotta balance out the unreliable to reliable ratio in the surveys. The ML hasn't had problems either, so that's why I'm joining. :)
Sorry, but I have no interest in doing all the work to provide data for anyone when I have no complaints. The only time I ever get involved in something like that is when I have a major problem. I think that is the way most people operate, which is one reason I worry about the reliability and validity of data collected on a Website like that. I have neither the time nor the energy to get involved. You will have to be the lone voice for those of us who have nothing to report--now or in the future. (I base my prediction about the future on my past experience, as do most other people.) But I wish you and our sociologist the best of luck!
mkaresh said:
There's hardly any work involved if your car never requires a repair. Just four approximate odometer readings a year, takes about two minutes.

I think most people will have a repair trip or two a year, so about ten minutes.

In response to the other guy, the method I'm using won't yield perfect information, but it will yield much better information than car buyers have access to today.

Mercedes owners are clearly must less interested in the research than most. So it looks like people who want reliability information on Mercedes will have to continue to rely on CR for the time being.
Now you're starting to worry me. You sound a lot like a typical anti-Benz "researcher." That is too bad because I was starting to consider participating...
mkaresh said:

My apologies. I forgot to consider that Mercedes owners are far more intelligent than people who buy other cars.

Actually, I suspect that the problem is that people who care about reliability information read CR, and as a result don't buy Mercedes. So there aren't many Mercedes owners who care about reliability information.

Just do me a favor and don't slur the research unless you've looked into the details of what I'm doing. Which I strongly suspect you have not.

For everyone else, it's a simple decision. If you feel no need for reliability information or feel that CR does a good enough job, then don't help out. If, on the other hand, you want to help provide a superior alternative to CR, this is the way to do it.
Now I am convinced: You are anti-Benz and are here just to try and make your data "look" more respectable. COUNT ME OUT!
tirona said:
buddy, your suspects are wrong, i did look very closely at your research. unfortunately, i have another view than yours of what real research is. but that's just my opinion.
you would have got better answers if you would have titled your thread "feedback on mercedes reliability", and not the boorish way you wrote it. don't forget that you are talking about a fine automobile. go sell your bullshit somewhere else.
I think he titled this thread exactly the way he was thinking about it, which is what got all of our attention in the first place. I think they call it a Freudian Slip...
asianml said:
I don't get how you guys come to that conclusion. He has valid reasons for what he says, and you guys aren't making it any better either. :rolleyes:
Sorry ML. As soon as you're old enough to get a driver's license you can vote too.
asianml said:
6 more months until license. I already drive. :rolleyes:

Whether or not I have my license is irrelevant to the survey and this thread. ;)
Well I just hope our researcher-friend reports his data to reflect how much experience respondent's have w/ the "ownership" of a particular car. Nothing personal, but I think it is extremely relevant to the validity of the outcome of his survey. This another concern I have about the Website survey methodology.
One question: Do you count discretionary trips to the shop? For example, if want to have my oil changed before the A or B service is called for, does that count as "a trip to the shop?" I do a lot of that kind of stuff, and would never relate it to a "problem" w/ my car.
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