Because existing sources of vehicle reliability information left much to be desired, in late 2005 I started conducting my own reliability research at TrueDelta.com. TrueDelta reports absolute stats like "trips to the shop" that make the differences between cars much clearer. Results are updated four times a year, so any significant changes in a model's reliability become apparent quickly.

Thanks to help from members of this forum, TrueDelta will provide results for the GL next month. I haven't been posting in any R-Class forums, because I assumed sales volumes were too low to get a decent sample size. However, the 2006 is halfway to the minimum, so I might have underestimated the odds of including the R-Class. If enough owners sign up to participate, I'll gladly provide results for this model.

Participants simply report repairs the month after they occur on a one-page survey. When there are no repairs, they simply report an approximate odometer reading four times a year, at the end of each quarter.

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

For the details, and to sign up to help out:

Vehicle reliability research

 

Next results for the GL in February. I'd like to get started on the R as well, but still need more owners to sign up to participate.

Auto reliability research

 

Closer, but not there yet.

 

Have been getting more 2007s, but not more 2006s lately.

Updated results for 92 other models next Wednesday. The 2008 C-Class, with 35 responses, will be in a second set of results with marginal sample sizes.

I'd like to have the R-Class in future results. This will depend on how many owners sign up and participate.

For the details, and to help make this happen:

Vehicle reliability research

 

Closer, but not there yet.

Vehicle reliability research

 

The 2006 is nearly 2/3 of the way, and the 2007 is nearly half way.

Help get your year included:

Vehicle reliability research

 

Updated results for the C and GL in August, and perhaps the E as well.

Would like to also include the R, but need more participants.

Vehicle reliability research

 

Slowly getting there.

Updated results recently posted for many other models.

TrueDelta Vehicle Reliability Survey results

 

Getting close with the 2006...

 

In about a month we'll start previewing the next set of results to participants. More remain needed to include the R-Class in the main survey, but owners can already participate in the real-world gas mileage survey.

Car reliability research

 

i just tried to input/view. this is a good idea, but frankly i found the design very difficult to use, and at the end, no data to speak of. i could not even provide input for my own mileage or repair service, let alone try to see others' results. just my $.02.
PL

 

Thanks for letting me know this. Improving usability is perhaps my top priority because others have had similar problems, and we're currently working on a redesign.

Problem is, we get almost no feedback that is specific enough to act upon. If you could, please contact me (michael @ name of site) so I can get a better understanding of the problems you encountered and perhaps how to fix them.

 

Well, I guess that's all the feedback I'm going to get. Some people find the site easy to use, others find it difficult. Would like to make it easy for everyone. Specific feedback helps.

Still need half a dozen more 2006s to add that year to the survey. Updated results for the C, E, and GL soon.

Car reliability research

 

Updated results for those other models recently posted:

Car Reliability Survey results

Still hoping to include the R in the survey. Just need more owners...

 

Please remember the R class population size is very small. Was it 26,000 in 2006; 18,000 in 2007? And less than 8000 in 2008.

I am registered for the survey for my Audi Q7 and Honda Odyssey, and will register for the R too if I ever get one for the right price. The monthly email reminders make it easy to log data. Keep up the good work, thanks.

 

No doubt that's a factor. In some cases we've gotten enough participants with even smaller populations, but this is definitely much more of a challenge.

 

The 2006 seems stuck 3/4 of the way to the minimum. Can someone unstick it?

 

I just registered the 09 I bought a few weeks ago.

 

Thanks, I certainly appreciate this.

The 2006 has now been included in the survey. Thanks, guys. So, assuming enough of those signed up respond, we'll start having results in February.

Additional participants would make this more likely, and enable us to cover additional model years.

Car reliability research

 

I know I would like to see results on the R sooner, have you considered posting across model years for cars that are few? The R as you know are limited in numbers and as the years progressed, fewer and fewer were built. 2006 had the highest production numbers and I suspect that is the only model year you will attain statistically significant numbers. On the other hand if you include later model years and footnote that, I think that would be of more value. The Rs had no major mechanical changes over the four years of production. What may be more relevant is distinguishing between engines (5.0, 3.5, 3.2 Diesel, 6.3L) rather than model years.

 

I think we can get enough 2007s and 2008s. The 2009s are going to be tough. Current number of owners signed up my model year:

2006: 25
2007: 12
2008: 9
2009: 2

The only time we combine two years is when the first of the two was a late intro, usually a very late intro. Even if the cars didn't change from year to year, age makes a big difference. One thing I might do in the future is group cars by odometer reading. This would be in addition to the current stats, though, not instead of them.

 

We'll have updated results for other Mercedes models soon. I'm hoping to have a result for the 2006 R with the following update, in February, but it's going to be tight since the number of people signed up remains close to the minimum.

To help make this result happen:

Car reliability research

 

Hoping to have some preliminary stats for the 2005 R-Class in February, but it's going to be tight. A few more participants could make the difference between having these and not having them.

Car reliability research

 

i just enrolled my '06 R500.

i did not have the TSB information to input...

 

Thanks for signing up, I appreciate it.

TSB information? Were you trying to post a common problem?

It looks like we'll have an initial result for the R-Class in May. Probably a partial result, but if enough owners sign up and participate we'll have a full result.

Not yet signed up? Details here:

Car reliability research