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Comment by nradov | Hacker News Reader

If electric cars are so simple, why is the Tesla Model S so unreliable?

https://www.truedelta.com/Tesla-Model-S/reliability-1095

Conversely, the Toyota Prius is one of the most reliable cars. Yet it is mechanically complex with both an internal combustion engine and an electric motor, plus a CVT. So clearly engineering skill and manufacturing quality are bigger factors than the drive train.

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The Model S drivetrain is reasonably reliable. Most of the reliability problems (and I believe they have an average score now, not great but not terrible) are other parts of the car. Tesla likes their unnecessary "cool" tech, which also tends to break. The Model S has the extending door handles, and the X has ridiculous doors. Not that it's limited to these aspects of the vehicle, of course.

Note that the Prius doesn't have a CVT the way you'd normally think of one. It has a fixed planetary gear set which is able to somewhat emulate a CVT by using two electric motor-generators in conjunction with the engine. I mention this only because "CVT" usually makes people think of painful friction-based transmissions, whereas the Prius's transmission is much simpler than even a normal transmission. Your point that engineering skill and manufacturing quality are the main factors is spot-on.

How unreliable are ICEs these days - maybe its just me, but I've never had an engine problem in nearly 20 years of owning cars. Electrical problems, suspension problems, drainage problems - had all of them but never had a problem with the actual engine.

Car guy here. Internal Combustion Engines have some pretty complex systems that pure electric systems don't need. Water cooling and engine oil spring to mind. Timing belts need to be changed, transition systems have problems with some regularity. (Granted, most performance electric cars have a transmission too, but you can almost get away without one, so I'm going to assume more simplicity of design)

Not arguing one way or another just providing data. My only electric car is an old converted Porsche. (Transmission is still there but you can basically slap it in third and leave it there) I'll never have to change the oil on that one again, and the electric motor is simple as can be. Battery management is kind of a pain, but that's because I don't have the kind of advanced battery management a mass market car would have.

I don't have enough data yet, but my experience suggests that electric cars will have a much lower maintenance load simply because of the reduced complexity. Of course all the automation and bells and whistles will still break, and the computer control systems will get wonky.

The last internal engine problem I had was with a 200cid (3.2 liter) inline six from Ford - the pistons had to be de-carboned after a cross-country drive. This was in 1985, so I blame the 55 mph national speed limit for not letting the engine run harder. Ever since - I just do 5000 mile oil changes and 3 year coolant changes, and all is well. They're really quite reliable these days, even as the complexity has gone up with turbos, direct injection, variable valve timing, and so on.

Maybe it depends on the age of your car and how you drive it? I've had 4 Honda Accords from an 88 up to an 07 that all started exhibiting the same engine problems around the 200k mile mark. Blown head gaskets, burning oil, timing belt issues, etc.

I assume you were replacing the timining belts on schedule. Given the near legendary reliability of the Honda Accord it makes me wonder if there's something about the way you drive.

Even so, 200,000 miles is not too shabby. I don't think we have useful data on electric vehicles with that kind of mileage.

I have a honda with 226,000 miles. Starts and runs like new.

I have replaced timing belt and water pump and motor mounts in addition to regular fluid changes. The timing belt and water pump work was proactive maintenance (the timing belt drives the water pump so they suggest replacing both at once since it's not really any extra work).

The motor mounts simply wore out. Not expensive to replace. Rubber mounts will wear out on a Tesla too, eventually.

What is a drainage problem?

I had a Passat a few years back and it had a design flaw where the tray that holds the battery has drain holes that can get blocked and if they do it overflows into the interior of the car.

I used to park my car under trees that dropped leaves which blocked the battery compartment drainage holes and as I am in Scotland it can get quite wet. Ended up with car filled with 1" of water.... Interior of car had to be stripped, dried out and put back in by the dealer.

I'm always tempted to test drive stylish German cars but I swear 90% of the maintenance horror stories I've heard in the last 15 years have involved a German car.

VW in particular has a pretty poor reputation for long term reliability (also see Consumer Reports et al). The stories I hear about American cars, by contrast, tend to be poor reliability soon after purchase (followed by solid long term reliability)

Not sure I would describe a Passat as "stylish" :-)

It's when you realize your OEM sunroof leaks just like an '70s aftermarket sunroof but there is a drain that keeps you from noticing. Or there was a drain, now it's full of dirt and debris and doesn't drain very well.

Window and trunk leaks

Turbo-diesel fuel injection pumps are ... not the most reliable thing to have in a car.

Because (personal opinion) the Tesla Model S isn't a particularly great car. Their success is largely in marketing, network, and visual appeal, not in the product itself.

If you pick a better (albeit less appealing) electric car, the reliability rate skyrockets. For instance, using your own source -- https://www.truedelta.com/Nissan-LEAF-vs-Tesla-Model-S-relia...

^ This. The Model S has a lot more in common with a mid-high range Mercedes or a low end Ferrari. Anybody who owns an exotic car like that will tell you, you do not buy those for the reliability.

It's also worth noting the Model S is, and is marketed to the audience for, a performance car. When you put down that kind of money, you're going to drive it like one. If you drove a Honda like a Ferrari you'd likely break a whole lot of it's "reliable" parts too.

A Mercedes limousine is hardly exotic, and neither is it unreliable.

What I found the most interesting in that comparison is that the Tesla, although having a lot more problems in other areas, had 0% issues in brakes and suspension.

Are they using some different much more advanced technology for those parts, or it's just some problem with the repair data?

I can only speak for the brakes. Teslas use regenerative braking on the motor before falling back to traditional frictional brake pads as I understand it. Essentially the motor is put in reverse and that drains off speed. That means less wear on the brakes and so they last much, much longer than an ICE car.

My ICE car has regenerative braking. So this is not something exclusive to the EVs.

Regenerative braking only works if there is spare battery capacity to absorb the energy. In general that requires a large battery to be useful. A normal car battery is nowhere near large enough and is generally topped off by the alternator.

My ICE car has regenerative braking as well, but I certainly didn't buy it for that, nor have I been able to discern the impact of it. I have driven EVs before and the regenerative braking is unmistakable.

Really? Don't you need a big electric motor for that... and some substantial lithium ion batteries? Is your ICE car a hybrid?

No, it is not a hybrid. But it uses brake energy regeneration to charge car's battery when you are not accelerating. The effect is not as pronounced as on EV cars, but enough to not use brakes often in normal traffic. In the context of the GP statement, it does reduce some brake pads wear.

ICE hybrids use regenerative breaking.

Actually the Prius is less mechanically complex than a normal ICE-Car. The planetary gear is really simple and you don't need parts which are prone to wear like a high torque clutch or a complex gearbox.

It is very reliable not despite but because of it's unique powertrain concept.

My friend put 100,000 miles on his Tesla in a year and was never stranded. He drove 30,000 miles on a known faulty motor.

It's not more unreliable than an ICE vehicle. It's significantly more simple in design and for repair. These claims are FUD.

This seems unbelievable. That is 500 charge discharge cycles at 200 miles apiece. Since there are only 365 days in a year This means that your friend was driving more than 270 miles a day meaning he was at 55 mph that is 5 hours a day. This is on the order of a professional trucker once you count weekends.

This also discounts the difficultly of finding well space out chargers. It also discounts the schedule of your friend. This also makes me wonder what time you have left to socialize with your 'friend'.

If you are going to make bold claims some explanation of the detail would go a long way towards making them seem plausible.

Well when someone gets a million dollar settlement from their employer and gets to keep their Tesla paid for outright and has nothing better to do for a year they just drive around the country. So that's what he did.

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