UPDATE: Majority of Early Tesla Model S Cars Could Require Drivetrain Replacement After 60,000 Miles, Data Suggests

December 10, 2015 Update: We’ve been informed by PIA that the study data from which this report is collated recorded actual drivetrain replacements among Model S cars rather than drivetrain failures. Since Tesla Motors was (for some time) replacing entire drivetrains of customers’ cars when receiving complaints about excessive noise or other faults, it is perhaps fairer to treat this study as one in which drivetrain replacements are tracked rather than total failures — although we will let the reader draw their own conclusions.

It’s no secret that when it comes to happy owners, the Tesla Model S electric car has the highest customer satisfaction of any car on the road today.

Even the venerable Consumer Reports, which recently removed its coveted red-tick recommendation due to a higher-than-average reported fault rate in its annual automotive reliability study, conceded that while Tesla cars appear to require more visits to the shop than some other brands, 92 percent of all Tesla owners would buy another car.

How reliable is the drivetrain on early Tesla Model S electric cars?

Even when their cars have to visit the shop, and owners find themselves with a far longer wait time for the repair than they once did, Tesla still seems to keep its customers happy.

That could soon change however, with news of a statistical analysis that suggests more than two-thirds of all early production Model S electric cars will suffer a drivetrain failure may require drivetrain replacement after covering just 60,000 miles. If true, it could put extra strain on Tesla’s already hard-worked service centres and perhaps even change the brand’s reputation among its owners.

We're not mathematicians, but this analysis suggests two-thirds of 2012 and 2013 Model S cars will suffer drivetrain failures after 60k miles.

We’re not mathematicians, but this analysis suggests two-thirds of 2012 and 2013 Model S cars will suffer drivetrain failures after 60k miles.

As our friends over at GreenCarReports explain, it has just completed an extensive analysis of data provided by 370 Tesla Model S owners via a Plug In America on-line survey form. The form, initially set up to allow Tesla Model S owners to share their experience with battery pack capacity and how it changes over time and distance driven, also asked owners to report their charging habits, driving habits, odometer reading and any replacements undertaken under warranty of the car’s battery pack, on-board chargers or drive unit.

The data from those cars as collated in October can be seen on the Plug-in America website, and seems to represent a wide enough range of  different Model S variants from 2012 thru 2014 model year cars located across the U.S., Canada and Europe. Since Plug In America made the raw data available for further analysis — and the data set included questions on drivetrain replacement — GreenCarReports’ Matthew Klippenstein (aided by a friendly reliability engineer) used the same data set to carry out a mathematical analysis on drivetrain failure rates.

Cleaning the data up to account for any errors in survey completion, a process which Klippenstein says he corrected errors favorably in Tesla’s favor, he then proceeded to execute a Weibull statistical analysis of the data in order to project probable drivetrain failure rates at given ages and mileages.

The result? Of those 2012-2013 Tesla Model S electric cars surveyed using the freely-available Weibull ++ software from ReliaSoft, Klippenstein concluded that more than two-thirds of the early 2012-2013 Tesla Model S cars made will likely suffer a drivetrain failure get a replacement drivetrain after 60,000 miles of use.

Tesla has said multiple times that the design which led to drivetrain failures has now been changed.

Tesla has said multiple times that the design which led to drivetrain failures has now been changed.

Using the same procedure, he notes that the Tesla Model S battery pack and onboard charger have a much longer life, with the on board charger for example likely to have a characteristic life of more than one million miles.

As Klippenstein notes, the data itself contained within the Plug In America survey is too small to be of use when it comes to later model-year Tesla cars since only a handful of 2014 model year cars were included in the survey. As a consequence, he negated to publish a statistical analysis of such a small data set.

At this point, we feel it’s important to note that the statistical analysis was carried out independently to Plug In America and as of the time of writing have yet to make an official statement on the analysis.

In response to questions from GreenCarReports over the analysis, Tesla Motors declined to answer specific questions about its own reliability data, replacement drivetrains carried out to date, or reliability of future drivetrains on later model year cars.

Instead, it issued the following statement, which we’re quoting from GCR.

Close communication with our customers enables Tesla to receive input, proactively address issues, and quickly fix problems. Over-the-air software updates allow Tesla to diagnose and fix most bugs without the need to come in for service. In instances when hardware needs to be fixed, we strive to make it painless.

I would point you to Elon’s previous comments, here and here, as well as whatConsumer Reports recently [wrote]:

Despite the problems, our data show that Tesla owner satisfaction is still very high: Ninety-seven percent of owners said they would definitely buy their car again. It appears that Tesla has been responsive to replacing faulty motors, differentials, brakes, and infotainment systems, all with a minimum of fuss to owners.

And Tesla’s attention to customer service has been effective. Almost every survey respondent made note of Tesla’s rapid response and repair time, despite the lack of a traditional dealer service network. For its early adopters, Tesla has made a practice of over delivering on service problems under the factory warranty…

Do you own a 2012-2013 Tesla Model S? Has your car suffered a drivetrain failure? Or are you an owner who has found the drivetrain to be reliable thus far?

What do you make of the analysis? And does it change your view of Tesla reliability?

Leave your thoughts in the Comments below.


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  • While a “statistical analysis” of the survey data (PIA) mwas conducted; the sample its based on is NOT a statistical representation of the Model S fleet. To have any statistical relevance, a random sample would be required.

    One thing not mentioned in the analysis was; if there is a difference between the 85 and 85p models? My expectation is the higher torque and power of 85p would have greater failure rate than other editions. (ie: due to greater mechanical stress)

    Of statistical significance is only ~20,000 U.S. Model S’s fall in a 2012-2013 delivery window. This is ~1/5 of Model S’s that Tesla has built. It is impossible to tell if the the 2014-2015 model’s have any correlation as few owners drive over 60,000 miles in 1-2 years of ownership.

    In general, how many 2012 vehicles with 60,000 miles? This means Tesla owners driving 20,000+ miles per year … vs. 12-15,000 for the general population. The high number of miles driven in a relative be short ownership period is statistically significant!

    • Michael Thwaite

      Torque might play into it, A friend of mine had his drivetrain splines fail spectacularly as he was demonstrating the acceleration off the line however, despite his embarrassment it wasn’t so bad. His co-workers were really impressed when, just a few hours later that afternoon, he had a complete replacement drivetrain installed, one that’s smoother than the original. That speaks to why Model S owners are a little more forgiving of this new technology; it gets fixed and comes back better than ever.

    • Zach Albrecht

      I have a 2013 with 56k miles and that is regular commute to work and every other weekend across state to visit family, which is about a 2 hour drive.

  • RedmondChad

    Like Brian said, the sample has to be representative. I believe most owners in the survey learned of it from threads about problems.

    Tesla definitely has a higher replacement rate than average and probably has a higher failure rate that average. But I see no way it is as high as suggested by this data.

    I have a 2012 with 57k miles. No problems so far.

    • Israel Navas Duran

      Wait, I had been told by so many evangelist sites that BEVs were much more reliable than ICE vehicles.

      • Cleber Zarate

        Are you here specifically to discuss the quality of Teslas over other manufacturers, or ICE versus BEV? Because they’re completely different subjects and the article is about the quality of Teslas.
        I don’t understand why some folks become so defensive when it comes to combustion engine versions electric engines; we all know it’s the future, it doesn’t matter whether you like Tesla or not.

        • Israel Navas Duran

          I rather discuss the gap between the bright hope and wishful thinking, and the dimmer and less glamorous reality.
          If BEVs are the future, why do you have a vested interest in them in the present?

          • Chris O

            The gap you suggests only exists for early Model S models. Too my knowledge most if not all other BEVs and even some highly complex PHEVs like the GM Volt do deliver on the promise of low maintenance.

            Tesla seems to have trouble keeping the extreme power some Model S versions from wearing out the transmission. It’s not even that big a deal, affected drive units are swapped out in an hour under warranty and only need relatively minor overhaul to bring them back in working order, no doubt with new parts that are better engineered to deal with the stress.

      • Anti Lord Kelvin

        Yes they are, and that ‘s the biggest problem for traditional car dealers that fear for their business survival. Even here in the “old Europe” (where there is not the same obsolete law about car dealers which NADA want to maintain in US), in dealers of car brands which have electric cars to sell, the guys in the shop almost always want to force you to buy a diesel car of the same brand!

  • JohnCBriggs

    I think there is a error in the text of the article.
    “Klippenstein concluded that more than two-thirds of the early 2012-2013
    Tesla Model S cars made will likely suffer a drivetrain failure after
    60,000 miles of use.”
    This should be “with-in” 60,000 miles. Only one-third will fail after 60,000 miles. Two-thirds will fail before 60,000 miles.

    Similarly, I think the title is not correct.
    “Majority of Early Tesla Model S Cars Will Suffer Drivetrain Failure After 60,000 Miles, Data Suggests”
    Rather the majority (two-thirds really) will fail before 60,000 miles. Or in the words of the original report “in 60,000 miles.”

  • willabeest

    problem is that a lot of these vehicles have low miles – warranty runs out of drive train – used tesla owners might have a problem.

    • Chris O

      There is an eight year warranty on the power unit. The problems are for Tesla that is learning an expensive lesson here.

  • Daveruns

    35,000 on my 2013 Model S and no problems. I bought the extended warranty, but the drive train already comes with an extended warranty. Personally, I am not worried in the least. I will never buy another ICE car in this lifetime, and probably nothing but another Tesla.

    • Israel Navas Duran

      You’ll have to get a stock of spare parts for when Tesla goes bankrupt.

      • Cleber Zarate

        Good thing Teslas only have half a dozen parts

        • Israel Navas Duran

          And that it’s fitted with laptop standard-size battery cells.

          • Anti Lord Kelvin

            The size is laptop standard-size, not the chemistry, nor the cell architecture and cooling.

      • Chris O

        Sure, the bad news just keeps poring in, even today:


      • Anti Lord Kelvin

        Don’t open the Champagne bottle to soon…
        For my part, I’m afraid for Tesla to that…their internet site will go blowing away when they will begin to receive reservations for the Model III next year.

  • J Mattioni

    Current Tesla owners are “early adopters” who put up with a lot more issues than the average consumer in exchange for having first access to the tech. It’s beyond me how Tesla can repair so fast without a dealer network. How do they do that?

  • Albertico

    Wasn’t this reported on some in 2013 and 2014? As I recall a lot of the Motor replacements were done because customers complained of Motor noise; so Tesla simply switched out the Motor with a new one.

    I think that’s a far cry from Drivetrain Failure as the article suggests. Sure there were some but nowhere near 2/3s.

    2012 and 2013 Model S were early production cars for a brand new car company; anyone expecting the first few to not have any problems must be delirious.

    Alas, what matters is how reliability behaves going forward.

  • Bubba Nicholson

    On the other hand, no Teslas have exploded in flames like my brother-in-law’s BMW sitting parked inside his garage now, have they?

    • Anti Lord Kelvin

      I saw a Statistic about two Tesla with beginning fire for the year 2013, one in 2014 and none of them so far in 2015. In the other hand around 250 000 ICE cars had set in fire in US for the year 2014 alone… Yes I know, Teslas are very few and there are more than 150 millions cars in US, but the last ones are based in a technology that there is around for a century now and with overwhelming amounts of money invested on by all the auto brands, unlike Tesla which is using electric drivetrain technology for only a few years and which have receive only a tiny amount of investments since it was invented an hundred years ago.

  • Amit Otal

    I have a Tesla Model S P85 manufatured in March 2013 and I have about 38k miles on it. So far I haven’t seen any problems. The servicing at the Rocklin Service center is impeccable coz they always give me a loaner whenever I give my car for tire-rotation or any other minor issues.

  • Chris O

    “Drivetrain failure” really sounds a bit dramatic than it really is as there this is not about cars leaving their owners stranded but mostly just some annoying noises that signal that a workshop must be visited within the next 10,000 miles or so. Also the ICE minded associate it with very expensive work done on complex ICE engines or complex ICE transmissions where exchanging the power unit is a minor operation as is the refurbishing of exchanged units and it’s all done under the eight year drivetrain warranty anyway.

  • Jason Tate

    The key here is Tesla is going to take the data they gather, and find a way to over engineer the transmission issues. Unlike the BIG 3 whom will just tell you tuff luck with your electrical, transmission, and motor problems.

  • P Donohue

    Regarding Typos:

    You: “…92 percent of all Tesla owners would buy another car.”

    Tesla & Consumer Reports: “Ninety-seven percent of owners said they would definitely buy their car again.”

    Why the 5% difference?