Model S [Official] Tesla Model S
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The Tesla Model S is a battery-electric, four-door full-size car produced by the American automaker Tesla since 2012. The automaker's second vehicle and longest-produced model, the Model S has both received mixed reviews from critics and also been described as one of the most influential electric cars in the industry.
tristatez28lt1
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http://www.roadandtrack.com/new-cars/news/a27567/two-thirds-of-early-tesla-model-s/
Report: Two-Thirds of Early Tesla Model S Drivetrains May Fail At 60,000 Miles
New analysis of survey data suggests the Tesla Model S owners may face serious reliability issues.
By all accounts, Tesla has been a major success. It's sold nearly 100,000 units of its Model S sedan, has a Model X SUV on the way, and despite overblown reports that it loses money on every car sold, it shows no signs of going bankrupt any time soon. In the world of automotive startups, no other company has come close to that kind of success.
But one of the biggest criticisms Tesla has faced is about its long-term reliability.Consumer Reports even went so far as to remove the Model S from its list of recommended vehicles. According to a new analysis of survey data from Plug-In America, it may even be worse than we thought. Two-thirds of early Model S drivetrains may need to be replaced before they hit 60,000 miles.
Green Car Reports conducted the analysis of the survey data, looking into long-term reliability of a total of 327 Model S sedans. Its conclusion is that 2012 and 2013 models face a serious reliability risk.
Tesla offers an eight-year warranty that will cover these issues, but it's concerning to see early models with failure rates nearly ten-times that of later models.
When asked for comment, Tesla didn't answer any direct questions but did respond with a general comment about the company's increasing reliability and strong customer satisfaction.
Report: Two-Thirds of Early Tesla Model S Drivetrains May Fail At 60,000 Miles
New analysis of survey data suggests the Tesla Model S owners may face serious reliability issues.
By all accounts, Tesla has been a major success. It's sold nearly 100,000 units of its Model S sedan, has a Model X SUV on the way, and despite overblown reports that it loses money on every car sold, it shows no signs of going bankrupt any time soon. In the world of automotive startups, no other company has come close to that kind of success.
But one of the biggest criticisms Tesla has faced is about its long-term reliability.Consumer Reports even went so far as to remove the Model S from its list of recommended vehicles. According to a new analysis of survey data from Plug-In America, it may even be worse than we thought. Two-thirds of early Model S drivetrains may need to be replaced before they hit 60,000 miles.
Green Car Reports conducted the analysis of the survey data, looking into long-term reliability of a total of 327 Model S sedans. Its conclusion is that 2012 and 2013 models face a serious reliability risk.
Tesla offers an eight-year warranty that will cover these issues, but it's concerning to see early models with failure rates nearly ten-times that of later models.
When asked for comment, Tesla didn't answer any direct questions but did respond with a general comment about the company's increasing reliability and strong customer satisfaction.
tristatez28lt1
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Full report:
Two-Thirds of Earliest Tesla Drivetrains To Fail In 60,000 Miles, Owner Data Suggests
Matthew Klippenstein
259 Comments25,205 viewsDec 9, 2015
Tesla Model S lithium-ion battery pack in rolling chassis [photo: Martin Gillet via Flickr]
With almost 100,000 on the world's roads, the Tesla Model
S electric car is a remarkable achievement.
It remains the longest-range electric car in volume production more than three years after it launched.
But reliability
issues with electric traction motors in early cars--those from the 2012 and 2013 model years--have dogged the earliest owners.
Now, a new analysis of data
provided to Plug-In America by 327 owners of early Tesla Model S cars suggests that as many as two-thirds of those early Model S drivetrains will need to be replaced within 60,000 miles.
This analysis has not been publicly disclosed before now. Before publishing this story, Green Car Reports asked several specific questions of Tesla Motors to help put the analysis in context.
Tesla declined to answer those questions. Instead, it issued general statements about its reliability. Both the questions and its statement are at the end of the article.
2013 Tesla Model S owned by David Noland, Catskill Mountains, NY, Oct 2015
Reliability: really a liability?
Since Consumer Reports dropped the Tesla Model S from its list of recommended buys due to a"worse-than-average overall problem rate", the barbs between the company's
supporters and detractors have only sharpened.
At issue is the significance, if any, of Consumer Reports' findings. Given that Mercedes-Benz--another highly successful luxury brand--also gets a worse-than-average rating, does it really matter? And should one also consider TrueDelta's more pessimistic assessment?
Do a drive experience rated at "103 out of 100" points and 97-percent customer satisfaction mean Tesla has little to worry about? Or do lengthening waiting times at service centers foreshadow a fall in customer loyalty and brand prestige?
Without the proper context, it all reduces to an electric-vehicle version of the fable about the blind men and the elephant.
But there's a trove of statistics that can contribute to the conversation. And a Weibull analysis of that data suggests that two-thirds of early (2012 and 2013) Model S cars can expect a drivetrain failure within 60,000 miles.
Tesla Model S electric motor and drive unit [photo posted by user Tam to Tesla Motors forum]
That's troubling.
Clearly, Tesla's eight-year warranty coverage on the drivetrain protects new and used buyers. And the company has said several times that it has made great leaps in quality as it gains experience in building the car.
Tesla's November update said the company has cut its failure rates by half, while CEO Elon Musk has expressed strong confidence in the improved drivetrains it has been shipping in recent months.
But the data set used to analyze drivetrain reliability includes about 10 times as many early (2012 and 2013) cars as recent ones from the 2014 and 2015 model years.
If enough recent buyers add their information, we may be able to improve the analysis and get statistical backup for the trend of improved reliability Tesla has mentioned.
Plug-In America's big (enough) data
The failure estimates above come from an analysis on data
from Plug in America's survey of Tesla Model S vehicles. Links at the bottom of the PIA page allow the data set to be downloaded.
In the survey, respondents provided a variety of information on their Model
S ownership experience, including total miles driven, whether they've had a motor swap (drivetrain replacement), and if so, what the odometer reading was at the time.
In October, when this analysis was run, the data set had 370 respondents. Not having any reliability
software handy, I asked a reliability engineer to crunch the numbers--and received the startling reply that the "characteristic life" of the drive train was about 50,000 miles.
In a reliability context, the so-called characteristic life is the age at which 63.2 percent of parts are expected to fail. This represents a survival rate of 36.8 percent, or 0.368. That value is the inverse of e, the base of the natural logarithm. In math terms, 1/e = 1/2.718 = 0.368.
Weibull Analysis of earliest 2012-2013 Tesla Model S drivetrains [plotted by Matthew Klippenstein]
The reliability engineer was careful to emphasize that the results were only valid if the data was correct, had no selection bias, and was random. While selection bias was definitely in play (only those customers who knew about the survey could choose to fill it out) the sample covered more than 1 percent of the total population of 2012 and 2013 Teslas (327 respondents for about 25,000 vehicles).
So selection bias and randomness were probably acceptably low. But on a line-by-line review of the Excel data file, I noticed a few transcription errors which indeed compromised the result.
When cleaning the data set, to give Tesla the benefit of the doubt--where respondents had reported a motor swap but didn't specify when it happened--I used the final odometer reading. (This would push up the characteristic life slightly.)
I repeated the analysis using free reliability software found online (I used Reliasoft, and there are other packages). For 2012 and 2013 Teslas, the characteristic life rose to about 57,000 miles. (The probability function predicted that 66 percent of drive trains would fail within 60,000 miles, giving the title of this article.)
Weibull Analysis of earliest 2012-2013 Tesla Model S drivetrains [plotted by Matthew Klippenstein]
By and large, calculations are only as credible as they are transparent, so the raw data and calculation method have been outlined at www.tinyurl.com/TeslaWeibull, along with the author's contactinformation
.
This should be enough for readers to duplicate the drive train analysis, and assess the Model S battery pack and onboard charger as well, the latter of which apparently has a characteristic life of about 1,000,000 miles.
Only 43 people in the data set owned 2014 and 2015 Teslas. And while this verges on a big enough sample--a statistical rule of thumb is that 30 to 50 random samples allow you to make accurate inferences about large populations--only a handful had even reached 20,000 miles.
That means that an analysis on that data would have been invalid. Far from measuring Tesla's success at mitigating the "wear-out" failure mechanism(s), it would reflect quirks in infant mortality and/or random mid-life failures.
There should now be enough 2014 Model Ses with enough road miles that we can refine our drivetrainreliability
trend analysis.
That will move us from discussing the yes/no question of whether or not the Model S is reliable to using crowdsourced data to evaluate its past reliability rate, and the pace of improvement in newer vehicles.
Why Weibull?
The calculations above are generally called a Weibull analysis, after the eponymous probability distribution. Its utility comes from the fact that it measures survival rates over time, which means inferences can be drawn from parts which haven't yet failed (called "suspends" or "suspended tests").
This is very important for long-lived parts, where it can take an impractically long time to run all samples to failure. (Calculations on early Teslas consisted of 77 failures and 250 suspends.)
2015 Tesla Model S 70D in new Ocean Blue color
In short, the Weibull analysis docks you points for items that have failed, and gives you credit for items that haven't.
Weibull distributions are power functions, meaning that they can be highly curved when plotted on a linear scale. For this reason, they're often plotted on a logarithmic scale, where they form nice straight lines.
Both linear and logarithmic charts have been included here. Failed tests are shown in blue, and suspended tests in red (along the bottom axis). In the bottom left, three values are given. Beta is the shape parameter.
Values above 1.0 represent failure rates that increase over time, indicating a component that wears out over time. Eta is the characteristic life noted above, at which point 63.2% of components are expected to fail. Finally, Rho is the correlation coefficient, which should ideally be close to 1.
No Tesla answers to questions
Before publishing this article, Green Car Reports reached out to Tesla with a list of specific questions to help us put this analysis in context.
Specifically, we asked:
Tesla Store Los Angeles [photo: Misha Bruk / MBH Architects]
Tesla declined to answer any of these specific questions. A company spokesperson sent the following statement:
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 what Consumer Reportsrecently [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 overdelivering on service problems under the factory warranty…
Two-Thirds of Earliest Tesla Drivetrains To Fail In 60,000 Miles, Owner Data Suggests
Matthew Klippenstein
259 Comments25,205 viewsDec 9, 2015
Tesla Model S lithium-ion battery pack in rolling chassis [photo: Martin Gillet via Flickr]
With almost 100,000 on the world's roads, the Tesla Model
It remains the longest-range electric car in volume production more than three years after it launched.
But reliability
Now, a new analysis of data
This analysis has not been publicly disclosed before now. Before publishing this story, Green Car Reports asked several specific questions of Tesla Motors to help put the analysis in context.
Tesla declined to answer those questions. Instead, it issued general statements about its reliability. Both the questions and its statement are at the end of the article.
2013 Tesla Model S owned by David Noland, Catskill Mountains, NY, Oct 2015
Reliability: really a liability?
Since Consumer Reports dropped the Tesla Model S from its list of recommended buys due to a"worse-than-average overall problem rate", the barbs between the company's
At issue is the significance, if any, of Consumer Reports' findings. Given that Mercedes-Benz--another highly successful luxury brand--also gets a worse-than-average rating, does it really matter? And should one also consider TrueDelta's more pessimistic assessment?
Do a drive experience rated at "103 out of 100" points and 97-percent customer satisfaction mean Tesla has little to worry about? Or do lengthening waiting times at service centers foreshadow a fall in customer loyalty and brand prestige?
Without the proper context, it all reduces to an electric-vehicle version of the fable about the blind men and the elephant.
But there's a trove of statistics that can contribute to the conversation. And a Weibull analysis of that data suggests that two-thirds of early (2012 and 2013) Model S cars can expect a drivetrain failure within 60,000 miles.
Tesla Model S electric motor and drive unit [photo posted by user Tam to Tesla Motors forum]
That's troubling.
Clearly, Tesla's eight-year warranty coverage on the drivetrain protects new and used buyers. And the company has said several times that it has made great leaps in quality as it gains experience in building the car.
Tesla's November update said the company has cut its failure rates by half, while CEO Elon Musk has expressed strong confidence in the improved drivetrains it has been shipping in recent months.
But the data set used to analyze drivetrain reliability includes about 10 times as many early (2012 and 2013) cars as recent ones from the 2014 and 2015 model years.
If enough recent buyers add their information, we may be able to improve the analysis and get statistical backup for the trend of improved reliability Tesla has mentioned.
Plug-In America's big (enough) data
The failure estimates above come from an analysis on data
In the survey, respondents provided a variety of information on their Model
In October, when this analysis was run, the data set had 370 respondents. Not having any reliability
In a reliability context, the so-called characteristic life is the age at which 63.2 percent of parts are expected to fail. This represents a survival rate of 36.8 percent, or 0.368. That value is the inverse of e, the base of the natural logarithm. In math terms, 1/e = 1/2.718 = 0.368.
Weibull Analysis of earliest 2012-2013 Tesla Model S drivetrains [plotted by Matthew Klippenstein]
The reliability engineer was careful to emphasize that the results were only valid if the data was correct, had no selection bias, and was random. While selection bias was definitely in play (only those customers who knew about the survey could choose to fill it out) the sample covered more than 1 percent of the total population of 2012 and 2013 Teslas (327 respondents for about 25,000 vehicles).
So selection bias and randomness were probably acceptably low. But on a line-by-line review of the Excel data file, I noticed a few transcription errors which indeed compromised the result.
When cleaning the data set, to give Tesla the benefit of the doubt--where respondents had reported a motor swap but didn't specify when it happened--I used the final odometer reading. (This would push up the characteristic life slightly.)
I repeated the analysis using free reliability software found online (I used Reliasoft, and there are other packages). For 2012 and 2013 Teslas, the characteristic life rose to about 57,000 miles. (The probability function predicted that 66 percent of drive trains would fail within 60,000 miles, giving the title of this article.)
Weibull Analysis of earliest 2012-2013 Tesla Model S drivetrains [plotted by Matthew Klippenstein]
By and large, calculations are only as credible as they are transparent, so the raw data and calculation method have been outlined at www.tinyurl.com/TeslaWeibull, along with the author's contactinformation
This should be enough for readers to duplicate the drive train analysis, and assess the Model S battery pack and onboard charger as well, the latter of which apparently has a characteristic life of about 1,000,000 miles.
Only 43 people in the data set owned 2014 and 2015 Teslas. And while this verges on a big enough sample--a statistical rule of thumb is that 30 to 50 random samples allow you to make accurate inferences about large populations--only a handful had even reached 20,000 miles.
That means that an analysis on that data would have been invalid. Far from measuring Tesla's success at mitigating the "wear-out" failure mechanism(s), it would reflect quirks in infant mortality and/or random mid-life failures.
There should now be enough 2014 Model Ses with enough road miles that we can refine our drivetrainreliability
That will move us from discussing the yes/no question of whether or not the Model S is reliable to using crowdsourced data to evaluate its past reliability rate, and the pace of improvement in newer vehicles.
Why Weibull?
The calculations above are generally called a Weibull analysis, after the eponymous probability distribution. Its utility comes from the fact that it measures survival rates over time, which means inferences can be drawn from parts which haven't yet failed (called "suspends" or "suspended tests").
This is very important for long-lived parts, where it can take an impractically long time to run all samples to failure. (Calculations on early Teslas consisted of 77 failures and 250 suspends.)
2015 Tesla Model S 70D in new Ocean Blue color
In short, the Weibull analysis docks you points for items that have failed, and gives you credit for items that haven't.
Weibull distributions are power functions, meaning that they can be highly curved when plotted on a linear scale. For this reason, they're often plotted on a logarithmic scale, where they form nice straight lines.
Both linear and logarithmic charts have been included here. Failed tests are shown in blue, and suspended tests in red (along the bottom axis). In the bottom left, three values are given. Beta is the shape parameter.
Values above 1.0 represent failure rates that increase over time, indicating a component that wears out over time. Eta is the characteristic life noted above, at which point 63.2% of components are expected to fail. Finally, Rho is the correlation coefficient, which should ideally be close to 1.
No Tesla answers to questions
Before publishing this article, Green Car Reports reached out to Tesla with a list of specific questions to help us put this analysis in context.
Specifically, we asked:
- How many motors has Tesla repaired or replaced in 2012 and 2013 Model S cars to date?
- What percentage of total cars does that represent?
- What does the company'sown reliability data indicate about the percentage of cars that will require motor replacements over the life of the vehicles?
- Musk said in November that reliability had doubled; how confident is Tesla that it has now fully resolved the reliability issues with earlier motors?
- What is the company's projection for failure rate in the motor(s) of current production cars?
- What would Tesla Motors say to owners (and future used-car buyers) of the early cars regarding the reliability of the motors?
Tesla Store Los Angeles [photo: Misha Bruk / MBH Architects]
Tesla declined to answer any of these specific questions. A company spokesperson sent the following statement:
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 what Consumer Reportsrecently [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 overdelivering on service problems under the factory warranty…
Rainer271
Kraftwagen König
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- Name
- Rainer
Tesla Model S facelift coming as soon as next week
The Tesla Model S showed the world that electric cars didn't have to be slow or ugly but it's getting a little long in tooth. In order to fix the problem, Tesla will reportedly introduce an updated Model S as early as next week.
Citing company insiders, CNET is reporting the updated model will receive a minor refreshing that includes an all-new front fascia. Details are limited but it will reportedly resemble the one used on the Model 3 and Model X. The car is also slated to have new LED headlights and a revised color palette.
The report goes on to say the facelifted Model S will have a more luxurious interior. Nothing is official but the car will reportedly have new seats as well as additional storage compartments.
There's no word on performance tweaks but the updated Model S is expected to be more expensive than its predecessor.
Tesla declined to comment on the rumors but released a statement saying the company is "constantly innovating and adding new features to our vehicles." Despite the denial, the statement confirmed Tesla has "... let customers know that some price changes will take effect in early April."
Source: CNET
The Tesla Model S showed the world that electric cars didn't have to be slow or ugly but it's getting a little long in tooth. In order to fix the problem, Tesla will reportedly introduce an updated Model S as early as next week.
Citing company insiders, CNET is reporting the updated model will receive a minor refreshing that includes an all-new front fascia. Details are limited but it will reportedly resemble the one used on the Model 3 and Model X. The car is also slated to have new LED headlights and a revised color palette.
The report goes on to say the facelifted Model S will have a more luxurious interior. Nothing is official but the car will reportedly have new seats as well as additional storage compartments.
There's no word on performance tweaks but the updated Model S is expected to be more expensive than its predecessor.
Tesla declined to comment on the rumors but released a statement saying the company is "constantly innovating and adding new features to our vehicles." Despite the denial, the statement confirmed Tesla has "... let customers know that some price changes will take effect in early April."
Source: CNET
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Full report:
Two-Thirds of Earliest Tesla Drivetrains To Fail In 60,000 Miles, Owner Data Suggests
Matthew Klippenstein
259 Comments25,205 viewsDec 9, 2015
Tesla Model S lithium-ion battery pack in rolling chassis [photo: Martin Gillet via Flickr]
With almost 100,000 on the world's roads, the Tesla ModelS electric car is a remarkable achievement.
It remains the longest-range electric car in volume production more than three years after it launched.
But reliabilityissues with electric traction motors in early cars--those from the 2012 and 2013 model years--have dogged the earliest owners.
Now, a new analysis of dataprovided to Plug-In America by 327 owners of early Tesla Model S cars suggests that as many as two-thirds of those early Model S drivetrains will need to be replaced within 60,000 miles.
This analysis has not been publicly disclosed before now. Before publishing this story, Green Car Reports asked several specific questions of Tesla Motors to help put the analysis in context.
Tesla declined to answer those questions. Instead, it issued general statements about its reliability. Both the questions and its statement are at the end of the article.
2013 Tesla Model S owned by David Noland, Catskill Mountains, NY, Oct 2015
Reliability: really a liability?
Since Consumer Reports dropped the Tesla Model S from its list of recommended buys due to a"worse-than-average overall problem rate", the barbs between the company'ssupporters and detractors have only sharpened.
At issue is the significance, if any, of Consumer Reports' findings. Given that Mercedes-Benz--another highly successful luxury brand--also gets a worse-than-average rating, does it really matter? And should one also consider TrueDelta's more pessimistic assessment?
Do a drive experience rated at "103 out of 100" points and 97-percent customer satisfaction mean Tesla has little to worry about? Or do lengthening waiting times at service centers foreshadow a fall in customer loyalty and brand prestige?
Without the proper context, it all reduces to an electric-vehicle version of the fable about the blind men and the elephant.
But there's a trove of statistics that can contribute to the conversation. And a Weibull analysis of that data suggests that two-thirds of early (2012 and 2013) Model S cars can expect a drivetrain failure within 60,000 miles.
Tesla Model S electric motor and drive unit [photo posted by user Tam to Tesla Motors forum]
That's troubling.
Clearly, Tesla's eight-year warranty coverage on the drivetrain protects new and used buyers. And the company has said several times that it has made great leaps in quality as it gains experience in building the car.
Tesla's November update said the company has cut its failure rates by half, while CEO Elon Musk has expressed strong confidence in the improved drivetrains it has been shipping in recent months.
But the data set used to analyze drivetrain reliability includes about 10 times as many early (2012 and 2013) cars as recent ones from the 2014 and 2015 model years.
If enough recent buyers add their information, we may be able to improve the analysis and get statistical backup for the trend of improved reliability Tesla has mentioned.
Plug-In America's big (enough) data
The failure estimates above come from an analysis on datafrom Plug in America's survey of Tesla Model S vehicles. Links at the bottom of the PIA page allow the data set to be downloaded.
In the survey, respondents provided a variety of information on their ModelS ownership experience, including total miles driven, whether they've had a motor swap (drivetrain replacement), and if so, what the odometer reading was at the time.
In October, when this analysis was run, the data set had 370 respondents. Not having any reliabilitysoftware handy, I asked a reliability engineer to crunch the numbers--and received the startling reply that the "characteristic life" of the drive train was about 50,000 miles.
In a reliability context, the so-called characteristic life is the age at which 63.2 percent of parts are expected to fail. This represents a survival rate of 36.8 percent, or 0.368. That value is the inverse of e, the base of the natural logarithm. In math terms, 1/e = 1/2.718 = 0.368.
Weibull Analysis of earliest 2012-2013 Tesla Model S drivetrains [plotted by Matthew Klippenstein]
The reliability engineer was careful to emphasize that the results were only valid if the data was correct, had no selection bias, and was random. While selection bias was definitely in play (only those customers who knew about the survey could choose to fill it out) the sample covered more than 1 percent of the total population of 2012 and 2013 Teslas (327 respondents for about 25,000 vehicles).
So selection bias and randomness were probably acceptably low. But on a line-by-line review of the Excel data file, I noticed a few transcription errors which indeed compromised the result.
When cleaning the data set, to give Tesla the benefit of the doubt--where respondents had reported a motor swap but didn't specify when it happened--I used the final odometer reading. (This would push up the characteristic life slightly.)
I repeated the analysis using free reliability software found online (I used Reliasoft, and there are other packages). For 2012 and 2013 Teslas, the characteristic life rose to about 57,000 miles. (The probability function predicted that 66 percent of drive trains would fail within 60,000 miles, giving the title of this article.)
Weibull Analysis of earliest 2012-2013 Tesla Model S drivetrains [plotted by Matthew Klippenstein]
By and large, calculations are only as credible as they are transparent, so the raw data and calculation method have been outlined at www.tinyurl.com/TeslaWeibull, along with the author's contactinformation.
This should be enough for readers to duplicate the drive train analysis, and assess the Model S battery pack and onboard charger as well, the latter of which apparently has a characteristic life of about 1,000,000 miles.
Only 43 people in the data set owned 2014 and 2015 Teslas. And while this verges on a big enough sample--a statistical rule of thumb is that 30 to 50 random samples allow you to make accurate inferences about large populations--only a handful had even reached 20,000 miles.
That means that an analysis on that data would have been invalid. Far from measuring Tesla's success at mitigating the "wear-out" failure mechanism(s), it would reflect quirks in infant mortality and/or random mid-life failures.
There should now be enough 2014 Model Ses with enough road miles that we can refine our drivetrainreliabilitytrend analysis.
That will move us from discussing the yes/no question of whether or not the Model S is reliable to using crowdsourced data to evaluate its past reliability rate, and the pace of improvement in newer vehicles.
Why Weibull?
The calculations above are generally called a Weibull analysis, after the eponymous probability distribution. Its utility comes from the fact that it measures survival rates over time, which means inferences can be drawn from parts which haven't yet failed (called "suspends" or "suspended tests").
This is very important for long-lived parts, where it can take an impractically long time to run all samples to failure. (Calculations on early Teslas consisted of 77 failures and 250 suspends.)
2015 Tesla Model S 70D in new Ocean Blue color
In short, the Weibull analysis docks you points for items that have failed, and gives you credit for items that haven't.
Weibull distributions are power functions, meaning that they can be highly curved when plotted on a linear scale. For this reason, they're often plotted on a logarithmic scale, where they form nice straight lines.
Both linear and logarithmic charts have been included here. Failed tests are shown in blue, and suspended tests in red (along the bottom axis). In the bottom left, three values are given. Beta is the shape parameter.
Values above 1.0 represent failure rates that increase over time, indicating a component that wears out over time. Eta is the characteristic life noted above, at which point 63.2% of components are expected to fail. Finally, Rho is the correlation coefficient, which should ideally be close to 1.
No Tesla answers to questions
Before publishing this article, Green Car Reports reached out to Tesla with a list of specific questions to help us put this analysis in context.
Specifically, we asked:
- How many motors has Tesla repaired or replaced in 2012 and 2013 Model S cars to date?
- What percentage of total cars does that represent?
- What does the company's
own reliability data indicate about the percentage of cars that will require motor replacements over the life of the vehicles?- Musk said in November that reliability had doubled; how confident is Tesla that it has now fully resolved the reliability issues with earlier motors?
- What is the company's projection for failure rate in the motor(s) of current production cars?
- What would Tesla Motors say to owners (and future used-car buyers) of the early cars regarding the reliability of the motors?
Tesla Store Los Angeles [photo: Misha Bruk / MBH Architects]
Tesla declined to answer any of these specific questions. A company spokesperson sent the following statement:
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 what Consumer Reportsrecently [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 overdelivering on service problems under the factory warranty…
Interesting report. Although electric cars are environmentally friendly they might not be environmentally sustainable. Tesla are quick to repair troubled cars but what will become of Model S that are past their warranty? Will they be easily repairable or will they be written off and discarded like a 4 year old iPhone.
If my memory doesn't fail me, 75% of all Porsches every produced are still on the road. I would bet against Tesla matching that stat in 10-20 years. However, few governments will accept planned obsolescence as cars are very difficult to dispose off. Demands of repairability will likely be put on Apple, Tesla and Google or else junky yards will be brimming of electric cars.
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I actually feel it looks better - more in keeping with the electric car "vibe". Too state the obvious: a grille was borne out of a necessity for IC cars - it was a facia for the vital radiator in water cooled cars.
- Messages
- 15,607
- Name
- Rolf
I know the grill in the Tesla is basically for show and not functional like most water cooled cars with front radiators, the front on the new FL looks a little bare in my opinion. I like the pre FL front better, its more stylish and cohesive.
tristatez28lt1
Tire Trailblazer
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- 6,578
While I agree the previous model looked better overall, I also disagree. I think the new front has more character and uses the "T" from Tesla as a full design theme for the grill. It works better for the brand also it is more distinctive.
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- 13,230
Agree, I just have to get used to all the empty sheet metal up front. OTOH, I wasn't a big fan of the older sort of oval fake grill either.
DjordjeC63
Vorsprung Visionary
- Messages
- 2,668
It looks far better than before without the round, 13 in a dozen grille. No doubt.
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Tesla
Tesla, Inc. is an American multinational automotive and clean energy company headquartered in
Austin, Texas. It designs, manufactures, and sells electric vehicles, stationary battery energy
storage devices from home to grid-scale, solar panels and solar shingles, and related products
and services. Incorporated in July 2003 by Martin Eberhard and Marc Tarpenning as Tesla Motors,
the company's name is a tribute to inventor and electrical engineer Nikola Tesla. In February
2004 Elon Musk joined as the company's largest shareholder and in 2008 he was named CEO.
Official website: Tesla
Official website: Tesla
