Real Or Imagined: Is The Tesla Model S Drivetrain Defective?

The reports of Tesla Model S drivetrain failures seemingly continue to grow everyday, but that doesn't necessarily mean its might just mean the car is misunderstood.

Jul 26, 2014 at 11:22AM

Tesla Model S In Europe
Tesla Model S-Driven Like No Other Car?

Recently, Edmunds sold their long-term Model S; but before they did so the car had four (yes, four) drivetrains replaced by Tesla Motors (NASDAQ:TSLA).  Motor Trend's long term car is working on its 2nd.

These high profile incidents do not make us ask the question "is drivetrain failure a common occurance in the Model S?"

Because it  is.

Model S Drivetrain

Tesla Model S Drivetrain

If you check out the latest numbers on a Tesla Motors Club poll, you will find that 75 (supposed) Model S owners have reported at least 1 drive unit replaced - 12 of which have had it replaced more than once.  (Fair disclaimer: There is always a couple jokers messing with the results of an uncontrolled poll like this. As a point of reference, TMC likely has somewhere around 5% of Model S owners as members)

To their credit, Tesla service has been doing a yeoman's job taking car of its clients.  Despite the many failure occurrences we have yet to hear of Tesla giving a Model S owner a difficult time in solving the problem (ie-replacing the drive unit entirely).

The problem for customers will arise however when Tesla's 4 year/50,000 mile warranty on the unit expires; that is when repairs reportedly greater than $10,000 a pop really start to hurt.

To ease the burden of that oncoming deadline, many owners have opted for the extended warranty – a great luxury to have; that is if you own your car in a location where the car is on sale and the warranty is available.

But is the Drivetrain defective?

We often get emails asking us to "look into the situation", or to try and get a firm price from Tesla on what a particular service operation will cost outside of the warranty period.

Even more common, "Is Tesla working on a fix?"

To date the main inference has been that the unit is defective.   And why not?  The failure rate is already well above the norm for a normal car.  Therein lies the may not be defective, it may just be well used.

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Now before anyone gets too excited and tells a story of an owner somewhere that had a failure through no fault of his/her own after a 1,000 miles ... yes that drive unit could be defective, we are not advocating that all failures are the owner's fault.  Sometimes things just break.  Heck, they could all be defective; but we seriously doubt it.

Electric cars are known for their instantaneous torque and silent performance.  They are known for making anyone with a driver's license into "Johnny Professional" when it comes peeling away off the line, or passing other cars on the road.  And as EV drivers, we like to feel that silent performance  underfoot ... a lot.  You find me a Tesla Model S that he/she doesn't, and I will find you a liar.  It could be that desire of the common man that is ultimately causing the bulk of drive unit failures.

Drawing from a personal example, I have tested many a car in my day; but the closest thing I ever got to owning a true petrol sports car of my own was a BMW Z4 M back around 2008.  I can recall truly pinning that car on just two occasions-to see "what she could do". 

It was great fun!

Naturally, I first found myself a nice quiet, out of the way piece of open road where few people lived, and then let it rip!  There was spinning tires, a growling engine – the whole nine yards of unbridled driving..  And then I was done; as this was my car I didn't fancy blowing her up and doing serious damage.

Audi R

The Tesla Model S Has Performance Specs Roughly Akin To An Audi R8

Now, when I bought my first electric car a few years ago, you know what I did the moment I was out of eye-shot from the dealership?  The exact same thing.  I put my foot to the floor and experienced the quiet awesomeness of all-electric acceleration.

Only this time, there wasn't the spectacle of an internal combustion engine making all persons within a half-mile wonder "what adolescent borrowed daddy's car and is now making a scene?"   I knew I didn't need any special occasion or location to do so.

And what of that little voice inside me that once told me to "not blow-up" my BMW z4?  She was no where to be found - because the markers I had long associated with a car being pushed to its limits weren't registering in my mind.

I probably pushed my new EV to the limit a half dozen times before it hit the family driveway for the first time.

And the first thing I did when I got home?  Took the wife for a spin to show here what it could do.  Then my friends.  Then later, complete strangers; something I never would have done in my Z4.  In total, my foot has hit the floor hundreds of times, maybe thousands of times in my plug-in vehicles.  I love's a cool sensation.  It is part of what owning an EV is all about.  That and hypermiling as far as one can past the stated range – it's a dichotomy to be sure!

The Tesla Model S has roughly the same performance of a new Audi R8 V10 Coupe – a classic "supercar" -  400lb-ft+ of torque, and a 0-60mph time slip of about 4 seconds...except of course that the Model S can seat up to 7 and weighs a 1,000 lbs+ more.

Now if I were to say, "I just don't know why my Audi blew up, I only drove the hell out of it a couple hundred times," I think people would be less inclined to call any shop time for that car a result of a defect, or to say that Audi had a situation on their hands; they would call it an expected outcome.

Many times you hear statements from those owners affected by a Tesla drive unit failure like "I really didn't push it that hard at all and it happened to me too!"

Although in most cases their statement is quite likely misguided, I do believe they are being honest...because they aren't hearing the screaming of a 10 cylinder engine, or getting the condescending looks that would normally be associated with what they are asking of their Tesla Model S sedan.

For some others, especially those more familiar with the rigors of maintaining a ultra-high performance automobile, I think they can appreciate the true sturdiness of the car as compared to its peers, and also accept the costly consequences over time for the thrill of the drive.

Or then again, maybe it's just defective.  Maybe there is a way to have a supercar have the longevity and reliability of a Honda Civic. 

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InsideEVs and author Jay Cole have no position in any stocks mentioned. The Motley Fool recommends Tesla Motors. The Motley Fool owns shares of Tesla Motors. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.

A Financial Plan on an Index Card

Keeping it simple.

Aug 7, 2015 at 11:26AM

Two years ago, University of Chicago professor Harold Pollack wrote his entire financial plan on an index card.

It blew up. People loved the idea. Financial advice is often intentionally complicated. Obscurity lets advisors charge higher fees. But the most important parts are painfully simple. Here's how Pollack put it:

The card came out of chat I had regarding what I view as the financial industry's basic dilemma: The best investment advice fits on an index card. A commenter asked for the actual index card. Although I was originally speaking in metaphor, I grabbed a pen and one of my daughter's note cards, scribbled this out in maybe three minutes, snapped a picture with my iPhone, and the rest was history.

More advisors and investors caught onto the idea and started writing their own financial plans on a single index card.

I love the exercise, because it makes you think about what's important and forces you to be succinct.

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