TrueDelta.com

[dhanson865]

I couldn't find that graph on the site. Is it available?

The user interface for getting to that is hidden.

You have to hover the mouse over "repair frequencies" at the top left and a drop down navigation menu will appear. Inside that menu click on "reliability trends" and it'll take you to the page you seek.

 

[mkaresh]

Sorry that it wasn't easier to find. We recently had to rush a redesign to better include mobile, and now that it's complete we need to go back and finesse some things. In general, navigation menus are now concentrated just below the header.

- - - Updated - - -

Our reliability stats for the Model S now include owner experiences through March 31, 2015. (Others are nearly a year behind.)

In terms of repair trips per 100 cars per year ("low" is best):

2014 Model S: 129, high, small sample size--judging from the 2013 a year ago, the stat would be lower (if still around 100) with a larger sample size
2013 Model S: 78, high (but an improvement from earlier)

Plus the percentage of cars with no repairs in the past year and those that required 3+ trips to the repair shop:

2013 Model S: 55, 3

We should have an initial stat for the 2015 next time. Based on a small amount of early data, it's looking much better.

We do very much need more of both the 2015s and the 2014s, as I'd really like to be able to provide precise stats for these years.

For repair descriptions, the stats for other cars, and to sign up to help improve this information:

Tesla Model S reliability

Note: if you have a 2014 Tesla produced after the introduction of the D models, please enroll it as a 2014.5.

 

[mkaresh]

Updated stats later this month. We continue especially need more cars for the 2014 and up.

If a car was produced after a significant mid-year change, enter it as a half-year car. The early Ds are 2014.5s. The rear-drive 70 and 90s will be 2015.5s--have people started taking delivery of these yet?

Join TrueDelta

 

[mkaresh]

Our reliability stats for the Model S now cover the year ending June 30, 2015. Others are over a year behind, and so report how these cars were doing when a year younger.

Repair trips per 100 cars:

2015 Model S: 88, high
2014 Model S: 102, high, small sample size -- continue to especially need more of these
2013 Model S: 72, high

Three months ago, based on early data, I thought I'd be reporting a much better stat for the 2015 right now. But this didn't happen.

We have two additional statistics, "Nada-odds" and "Lemon-odds", to indicate the percentage of cars with no repairs in the past year and those that required 3+ trips to the repair shop:

2013 Model S: 48, 11

Additional participants would be helpful. We have the new 70, 90, 90D, and P90D listed as 2016s. Enrolling them and other recently produced Teslas as 2015.5s will also work.

For the descriptions of all reported repairs, results for other models, and to sign up to help improve this information:

Tesla Model S reliability ratings and comparisons

 

[AmpedRealtor]

How are we to reconcile TrueDelta negative with Consumer Reports positive?

 

[Max*]

How are we to reconcile TrueDelta negative with Consumer Reports positive?

People on forums are always complaining about stuff.

 

[ProSkeptic]

People on forums are always complaining about stuff.

That, and arguing.

But seriously... I read Michael's take on CU's data collection a few years ago, and it's a big reason why I take their information with a large grain of salt.

 

[Zaxxon]

But seriously... I read Michael's take on CU's data collection a few years ago, and it's a big reason why I take their information with a large grain of salt.

This. I'll let Michael respond to the question, but I'll mention that I've been using (and following) TrueDelta for many years. His blogging about CR was one of the first things that intrigued me about his (then) new site.

 

[mkaresh]

How are we to reconcile TrueDelta negative with Consumer Reports positive?

First off, it's necessary to separate CR's road test scores from their reliability survey ratings. The former, not the latter, are what they have been so positive about. They tend to de-emphasize reliability when talking about the Model S.

Second, their current ratings are based on a survey conducted in April 2014, nearly a year and a half ago. They'll be updating them to reflect an April 2015 survey in about a month--and they'll still be a few months behind.

Third, and this is the big one, they instruct participants to report "only problems you considered serious." If people really like the car, possibly in part because of what they've read in CR, they are less likely to report a problem. If they expected some problems because the car and the company making it are both new, they are less likely to report a problem. If they feel they received good service, they are less likely to report a problem. Conversely, if people don't like the car, the dealer, or the manufacturer they can report virtually anything as a serious problem. Many people report rattles. Some do not report transmission replacements because they got a loaner car and the warranty covered everything. Combine all of these factors, and Tesla owners can HONESTLY report far fewer problems on the CR survey than they do on ours, which instructs people to report ALL repairs.

My issue with CR's approach is that it introduces a large amount of subjectivity into what is being measured, such that in the end it's unclear how much they're measuring reliability and how much they're measuring how people FEEL about the car, about dealer service, about the manufacturer, and so forth. A key advantage of their approach is that they don't have to thoroughly screen responses, since they have no clear, objective criteria of what should and should not count in their analysis. With a subjective question, you can assume that if someone reports something as a problem, then it counts as a problem. And if they don't report it then it should not count. With objective criteria like we use, every response must be thoroughly checked and adjusted as necessary to correct errors. This is far more practical with sample sizes like ours rather than sample sizes like theirs.

The results are not contradictory if you know what they actually represent. Based on CR's results, owners felt that the Tesla Model S had an about-average number of serious problems during the year ending in April 2014. Based on our results, the cars required far more repairs than the average car during the year ending June 2015.

 

[mkaresh]

As has been discussed elsewhere on this forum, Consumer Reports has now downgraded their reliability rating for the Model S and no longer recommends the car. I believe the factors discussed in my previous post are to blame rather than any actual decline in the cars' reliability. Owners have justifiably cut Tesla a lot of slack as a new company producing a new car with a lot of new tech, but they're starting to do this less.

In our much more objectively worded survey, the Model S continues to have a high repair frequency, but it contrary to CR we see that reliability has been improving, not declining.

A big thanks to everyone who has been helping. Additional participants would be very helpful, especially for the 2014 (pre-fall update) and the latest cars (2015.5 in our survey).

If you do not see the specific powertrain of your car listed, contact me. Most likely the model year needs to be adjusted (2014 to 2014.5 or 2015 to 2015.5).

To sign up to help:

Join TrueDelta

 

[Vitold]

Given small sample, and voluntary reporting, truedelta results are meaningless as far as overall reliability goes. Truedelta is useful to track what types of fixes are needed and to track trends across model years, but that's pretty much it.

In addition, Tesla maintenance schedule has not been yet defined which hurts it's reliability stats. For example, ICE's timing chain/belt or head gasket replacements are routine maintenance. I bet some Tesla DU 'failures' could have been prevented by replacing some part after x miles - before noises start but Tesla does not do that at the moment.

 

[mkaresh]

We've updated our reliability stats for the Model S to include owner experiences through September 30, 2015. Repair frequencies, in terms of repair trips per 100 cars per year:

2015 Model S: 72, high (includes all cars after the fall 2014 changes)
2014 Model S: 62, high, very small sample size (only includes 8-9 months of production)
2012-2013 Model S: 60, high

While these frequencies remain high, that for the 2012-2013 has steadily improved every quarter for the past five--as seen in the attached graph. Does this also seem to be the case at the forum? Do owners feel like they've had fewer issues with the cars after early problems were fixed?

We have two additional statistics, "Nada-odds" and "Lemon-odds", to indicate the percentage of cars with no repairs in the past year and those that required 3+ trips to the repair shop:

2012-2013 Model S: 53, 3

In other words, a little over half of these cars required no repairs at all in the past year.

We'll have further updates in February and in May. The more owners participate, the more comprehensive and precise these will be.

To see how competitors compare, and to sign up to help improve this information:

Tesla Model S reliability ratings and comparisons

 

[veryannoyingname]

Is this data for USA models only or do you accept data for other countries too.
Is there any data for EU and UK models. Norway has loads of cars of the EU VERSION and am curious if there are any differences in reliability between USA and UK / EU models. If anyone has any links for reliability of UK and EU models please post here. Interested in the wait times for getting service appointments due to hearing anecdotal reports of 3 to 6 months wait times for repairs in Norway. More specifically interested in any information for the UK please.

 

[mkaresh]

Most of these cars are in North America, but some are in Europe. There seems little reason to separate them since nearly all of the parts are the same, and they're assembled in the same factory.

 

[hybridbear]

Third, and this is the big one, they instruct participants to report "only problems you considered serious." If people really like the car, possibly in part because of what they've read in CR, they are less likely to report a problem. If they expected some problems because the car and the company making it are both new, they are less likely to report a problem. If they feel they received good service, they are less likely to report a problem. Conversely, if people don't like the car, the dealer, or the manufacturer they can report virtually anything as a serious problem. Many people report rattles. Some do not report transmission replacements because they got a loaner car and the warranty covered everything. Combine all of these factors, and Tesla owners can HONESTLY report far fewer problems on the CR survey than they do on ours, which instructs people to report ALL repairs.

My issue with CR's approach is that it introduces a large amount of subjectivity into what is being measured, such that in the end it's unclear how much they're measuring reliability and how much they're measuring how people FEEL about the car, about dealer service, about the manufacturer, and so forth. A key advantage of their approach is that they don't have to thoroughly screen responses, since they have no clear, objective criteria of what should and should not count in their analysis. With a subjective question, you can assume that if someone reports something as a problem, then it counts as a problem. And if they don't report it then it should not count. With objective criteria like we use, every response must be thoroughly checked and adjusted as necessary to correct errors. This is far more practical with sample sizes like ours rather than sample sizes like theirs.

The results are not contradictory if you know what they actually represent. Based on CR's results, owners felt that the Tesla Model S had an about-average number of serious problems during the year ending in April 2014. Based on our results, the cars required far more repairs than the average car during the year ending June 2015.

This is why I also don't trust CR. I've been using TrueDelta for around 5 years to track & report repairs. I find it useful because it also enables me to look back on previous vehicles & see just how many issues we had, it helps to mesh reality with perception in my memory. I've been watching the TrueDelta stats on the Model S, hoping it will improve. It's good to see things improving over time.

 

[Cosmacelf]

Yes, as an owner of an almost 3 year old Model S, it tracks my perception. I would like to point out, that while I have had issues attended to, none have been urgent, and all were handled efficiently and with minimal impact to me.

 

[mkaresh]

The graph I posted earlier definitely suggests improvement.

One concern I have is that they'll get distracted by the Model X and then the Model 3, and won't be able to make improving quality with the Model S a high priority. It's very difficult to achieve the low repair frequency of the average 2015 car--22 per 100 in the past year, and most of these minor. Most auto companies had to feel a lot of pain and expend decades of effort to improve beyond Tesla's current quality levels. Even 20 years ago today's quality levels appeared impossible.

 

[mkaresh]

The next round of the survey begins in a few days. As always, additional participants would be helpful (especially those with 2014s or the latest revision).

Join TrueDelta

 

[mkaresh]

One important clarification. One member recently suggested that some Model S owners have not reported repairs performed by Rangers because the survey asks if the "car has returned from a repair trip." It's simply not practical to word this question so it's literally correct for every possible repair situation--the question would become so wordy that no one would read it.

Essentially, if the car had something wrong with it, and something was done to fix this, then it should be reported.

If anyone needs to add a non-recent repair to their record because they did not think Ranger repairs counted, please email or PM me. I can add it easily.

 

[mkaresh]

We've updated our reliability stats for the Model S to include owner experiences through the end of 2015, about eight months ahead of other sources. In terms of repair trips per 100 cars per year--lower is better:

2015 Model S: 56, high
2014 Model S: 52, moderate, small sample size
2013 Model S: 54, moderate

We have two additional statistics, "Nada-odds" and "Lemon-odds", to indicate the percentage of cars with no repairs in the past year and those that required 3+ trips to the repair shop:

2013 Model S: 58, < 1

These stats have been improving, and are much better than earlier. A reminder: anything done to fix a problem should be reported.

For the repairs behind these stats, reliability information on other models, and to sign up to help improve this information--especially need more 2014s and 2016s:

Tesla Model S reliability ratings and comparisons