The statement that electric motors have fewer moving parts so they last substantially longer is a fallacy that electric car proponents have been spreading for years. There are still many, moving parts which require servicing and can fail at a rate of similarly serviced gas engines. In fact servicing (rewinding) is quite a labor intensive and expensive operation, given the price of copper or other conductive material used in the construction of electric motor.
Should a motor fail. The cost is significant.
I like the idea of an electric car, but the truth is the motors do fail. They require maintenance in the static environment of a factory or they will fail, a car on the open road with harsh environmental factors it will be hard on them.
But the biggest lie about electric car maintenance is that is lower. Its not. 90% of a vehicle's maintenance has nothing to do with its motor. It's tires, brakes, lighting, lubricants(yes electric motors need oil changes too), and power systems. Which I suspect will be more extensive here since there will be countless OS upgrades to both the drive systems and the power control units.
Its not possible at this time to compare gas engine maintenance w/ electric motor maintenance because its not apples to apples. You can however look at replacement cost as an indication of serviceability. A 400hp electric motor costs about $24,000 vs. a 400hp gas engine at about $6000.
The gas engine is still far more economical at this point even factoring in fuel costs.
>400hp electric motor costs about $24,000 vs. a 400hp gas engine at about $6000.
You think the motor in the Telsa costs 24 large? I'd say you are off by an order of magnitude.
What are the big-ticket repair items on an gas car? The engine and the transmission. Electric motors are maintenance-free, and the Telsa doesn't have a transmission. Also, there is minimal vibration and heat compared to a gas engine.
I would guess maintenance costs on an electric car are 1/4th of a gas car. Except the battery pack, of course. That will eventually need to be replaced.
On what basis? I know he didn't cite, and I'm not trying to put the burden of proof on you, but I'm curious why you think this. As in, I'd like to see some data (from either side).
I did some brief searching and he is correct that [45]00 HP brushless motors seem to go in the low five figures (at least on Ebay, which I know is not representative of Tesla's costs). I'm happy to believe Tesla's cost less, but I'm not sure.
On the basis that it is the size of a (very large) watermelon. What's it made of? Copper and steel and aluminum. $1000 of materials and $1000 in labor.
This manner of cost estimation is not convincing to me, for reasons that should be obvious to anyone. There are plenty of small things that cost a lot of money, because, perhaps, of the precision or techniques required to manufacture them or their components, or the dearness of the materials that compose the minority of the object.
I often come to the wrong conclusion when "just thinking" about it, especially in domains where I am not even a novice. Also, the fact that I don't find listings for 500hp brushless motors for <10k online calls into question the results of your thought experiment.
I can see where you get your belief -- I wasn't questioning that it is a reasonable one to hold. But I am asking for evidence that compels me to a confidence level I'd actually bet on. Data will be required. Thought experiments are not sufficient.
(Don't get me wrong, I'm not accusing you for failing to provide data. It may not be publicly available. And it is not your duty to give me this. But that is what I am asking for, and if you don't have it, you don't have what I want, your duty or no.)
You're making an assertion that runs counter to the common wisdom that electric cars will require less maintenance, so the burden of proof is on you.
The fact that you can't find brushless motors online that retail for less than $10k is not convincing, because it's a new use case, a unique design, and they're not selling them outside of cars. You don't know what the pricing is. As far as materials, that amount of copper isn't going to help it get to $10k.
EDIT: Oh sorry, I mistook you for the originator of this thread, jesusmichael. He asserted that, not you.
So your logic tells you that Tesla has "invented" an electric motor, so rugged that it can withstand that riggers of being inside a consumer vehicle on the open road with a novice operator, in various environmental conditions, that is a fraction of the cost of similarly powered electric motors that operate in static environments, such as a factory floor, with experienced operators and fixed maintenance schedules? Wow.. I have a bridge to sell you... you're not the guy to be discussing "common wisdom"...
Novice operator - the operator of the motor itself is the control electronics, not the driver. If the operator can do something to damage the motor, the design is faulty.
Industrial electrical motors and control electronics like those in robots have completely different tolerance requirements, and are made in relatively low volumes, and so there are fewer units to support development costs.
relatively low volumes? Nearly every machine in every factory in the world has an electric motor of some ilk.. Have you ever been in a factory?
The novice operator and put the machine itself in a situation in which it will not operate correctly, extreme cold, flood, etc. Steep grade + Lead Foot = burnt coil. While I do agree with you to some extent... there is some user input... but motors in Tesla... are still pretty complex..
I meant that the individual models of industrial motors are made in low volumes relative to the motors in a mass manufactured product like the Model S, not that there weren't many electric motors in industry. There obviously are quite a lot of them involved in industry, but they come in many types, each of which has to pay back its own development budget.
I never made that assertion. I'm only asking questions.
"Common wisdom" does not create a burden of proof for detractors, especially if the common wisdom is never, that I can find, backed up with evidence. That is absurd. It would be like saying that the burden is on non religious people to prove that Jesus is not god because billions of people think he is.
Yeah, sorry about that, I got you mixed up with another poster.
But I do think that it's backed by evidence. There's no multi-gear transmission, and while there are moving parts, and other than the wheels/brakes, they aren't bathed in liquids that need regular changes and they aren't subjected to combustion and various other destructive forces that an ICE is constantly subjected to. There's relatively little force transmission hardware needed. The motors themselves should be relatively low-friction, and mechanically are much, much simpler than internal combustion engines (compare a breakdown of the parts of an ICE vs. electric motor, they're in completely different leagues). Air-fuel mixture control, turbochargers, and all manner of other chemical energy management systems are replaced by solid state electronics.
Given how vertically integrated Tesla is, this is the right approach. Include a factor for time on capital equipment (number which can be produced per year per machine, cost of machine, cheap cost of capital, wear on machines, depreciation over lifetime) and you'd probably be good (maybe $3k total for the part?)
If it's a commodity item (like most electric motors, but maybe not the one in the Tesla), with a competitive market, you might be able to estimate cost by looking at open market pricing, but for something like SpaceX, that clearly doesn't work.
Tesla is closer to SpaceX in thinking than it is to most car companies, especially startup car companies.
1. That motor is a low speed motor, as such it is massive. It weighs 3044 pounds. The Tesla motor runs at nearly 10 times the speed, and ought to be roughly a factor of 10 lighter.
2. See how the price drops by almost 10% when you buy more than 5 of these motors? Now imagine you are buying 20,000+...
3. You can bet the manufacturer of the motor (Baldor) did not get $25k for it. I imagine the markup for the reseller is of the order of 30-50%, on top of other costs such as transport. These do not apply to Tesla.
I am pretty sure even $6000/unit is an over-estimate.
I have some information from an occasionally reliable source that the entire car costs around $20,000 to make. This is the "incremental cost", after tooling, R&D etc has been paid for. This is apparently about the same as a top level mass produced luxury Benz - for the Benz, the much higher inherent production cost is offset by the scale and efficiency of their production line.
The comparison is retail to retail... Not wholesale cost. I'm sure if you need a motor, because yours failed after 6 years, they aren't going to sell it to you for wholesale. And if they are marking up the cost of the car by 400% than if their motor is $5000... you'll be paying $20k
That $20k motor is much less advanced than what's in a Tesla... So @ $24k I think its a bargin... what is the rest of the car? Aluminum and Plastic and a couple of computers...
"Oil change" for an electric motor is fundamentally nothing like the oil change you do for an internal combustion engine. A piston engine operates at much higher temperatures, and cannot fully isolate leakage from oil compartment, causing a tiny amount of oil to get burned with fuel as it operates.
"Oil change" in an electric motor is much more like lubricating other moving parts of the car or other machinery, not the engine of a gasoline car.
In addition to that, an electric car (at least the Model S), is much much simpler in design. The motor is basically connected directly to the wheels, removing a ton of parts in the process. It's simpler to start and simpler to cool. Yes, it can still break, but it's much more similar to your hard drive failing than your traditional car.
The roadster has a single speed transmission that connects the axels to the wheels. It would be unwise to connect a motor directly to the wheel. The axles are basically the same as with the Prius or any other car for that matter with wheel bearings and CV joints.
For all the parts that are removed there are a couple added, in the recombinant braking system, power control systems and programmable suspension.
The grease in the sealed bearings will break down at some point. A spinning motor especially one in a magnetic field has a very low tolerance for vibration and balance. There is also a great deal of heat generated at high torque. I hear the S is going to have liquid cooling. So there is another system that will need to be addressed.
I would hardly call a Tesla a simple design. Its in fact very complex.
Tesla doesn't seem to think their motors require oil changes. Are you saying that they're just letting their owners destroy the motors by going without necessary maintenance?
Also, do you have a source on the $24,000 for their motor? That seems awfully high given that the thing is about the size of a loaf of bread. Hard to see what could make it so expensive.
In addition to the motor, the schematic diagrams above seems to many moving parts that typically need work by 120,000 miles. Eg: steering (likely) differentials (likely) and in various parts of the suspension (internal). Whilst the specifics may be debatable, most of these items are wear items and require fluid changes and/or replacement internals. Things also like wheel bearings will need some preventive maintenance. If this spreadsheet was for a 50,000 mile interval or a lease perhaps you'd overlook these. A chassis for $30K+ with 120k on the clock would bring customers looking at the cost of these services, I would venture. One way luxury brands (at least in the past have) maintained the price premium of their new vehicles is to make the 100K and up maintence quite expensive.
Why are you specifically wondering about th motor oil? Do you think that getting some to admit teslas don't need oil changes will some how prove that the power windows won't fail; rocks will never crack the windshield; one headlight won't mysteriously stop working after 6 months; tires won't lose tread etc.
Because that's the actual maintainance cost of a car. Modulo nobody's engines need replacing in 10 years. Oil changes are 30 bucks once a year at a Walmart/jiffy lube.
The post that kicked this particular thread off even said as much but everyone seems more interested in arguing about the possible cost of the worst case than considering the actual costs of the probable cases: all the little shit.
Because I saw the statement that "electric motors need oil changes too" and I wondered what exactly that meant. Please don't assume that every single person in a discussion must have some kind of ulterior motive. I'm not trying to prove anything about the overall maintenance cost of a Tesla. I just want to know what kind of "oil changes" its motor needs and how that fits in with the official maintenance schedule, because I like to know things and that one piqued my curiosity.
I'm sure it involves some sort of oil or grease or something of that nature.
But that alone doesn't tell me much. There's a pretty wide gulf between a gas motor that needs regular preventive lubricant changes every few thousand miles and other parts, e.g. wheel bearings, that are sealed and lubricated for the life of the part and can be expected to last a couple hundred thousand miles.
"Electric motors need oil changes too" implies something closer to the former than the latter.
I think it's just sealed bearings. The tesla motor is essentially the same as the spindle in a CNC, and those do not require lubrication but do need bearing replacement.
My source is an industrial electric motor supplier. Google "400hp electric motor"
I'm not saying tesla's require oil changes as a gas engine does... oil will last quite a long time when not contaminated by hydrocarbons.
But even sealed bearings need to be repacked after so much wear. To parts can't move against on another without generating heat, which will degrade a lubricant and allow wear.
The mistake you're making is assuming that the single unit price of a low volume device like an industrial electric motor in any way reflects its component costs. High tech low volume engineering is dominated by R&D costs, one off manufacturing costs and margin. You could apply your logic (it would cost me $25,000 to buy one so therefore it costs Tesla that as well) to almost any item of consumer electronics and you'd find that your cost estimation was an order of magnitude (at least) above the retail price of a completed device. Try pricing a washing machine based on the cost of its component parts online - you won't be able to do it for anywhere near the cost in store.
When you build large numbers of integrated devices (be they washing machines, cars or cell phones), individual unit costs of components are always much lower. That's why we mass produce things.
The "mistake" you are making is that you assume Tesla has "invented" an electric motor, so rugged that it can withstand that riggers of being inside a consumer vehicle on the open road with a novice operator, in various environmental conditions, that is a fraction of the cost of similarly powered electric motors that operate in static environments, such as a factory floor, with experienced operators and fixed maintenance schedules? Wow.. I have a bridge to sell you...
Tesla uses a induction motor... which is AC and they use a frequency control unit to modulate the speed of the motor. So frequency isn't really a consideration...
Here's a perfectly written comment, downvoted. I don't agree with the conclusion, I question several of the premises, but I can't understand downvoting based on agreement. The comment is good, well written, and adds to the discussion. It should be upvoted.
Are there voting guidelines for HN? Am I in the wrong here?
That comment has so much bullshit in it - here is a sampling:
>The statement that electric motors have fewer moving parts so they last substantially longer is a fallacy
No, it is true on all counts. I'd explain in detail, but this is so weird I dont really know where to start.
>90% of a vehicle's maintenance has nothing to do with its motor
Rubbish. In a gasoline (or diesel) powered car, the majority of maintenance is to do with the engine and its auxiliary systems such as fuel delivery, ignition, cooling, starting etc.
>electric motors need oil changes too
This is the best one of the lot. Not sure if a moron or a troll.
I should have stated "electric vehicles" vs "electric cars".
However you really don't have the slightest idea about the motor that's in the Tesla. Which is a 3 phase induction motor. There's a lot that goes into converting DC battery power to AC and then controlling the torque. Heat is another issue that will have to be dealt with as well and the latest announcement from Tesla is that they will be adding a water cooled system to the induction motors in the future.
A property serviced gas motor doesn't need much more beyond oil and spark plug changes and can last for several hundreds of thousands of miles. The majority of the consumables are in the wheel systems, tires, brakes, suspension, bearings, heating and cooling the cabin, etc.
I'm sure you're an idealistic kid that thinks green is good... and knows that ignition=starting, but the fact remains that gas engines have a 100 years of service history and electric car motors don't which means...
>I'm sure you're an idealistic kid that thinks green is good
I am the engineering manager for the Australian branch of one of the world's largest oil and gas contractors. I graduated with 1st class honours in mechanical engineering, and have 25 years of work experience. Idealistic - yes, thinks green is good - yes, my career notwithstanding. Kid - I wish...
>However you really don't have the slightest idea about the motor that's in the Tesla ... ... There's a lot that goes into converting DC battery power to AC
Actually, I have a pretty good idea about both of these things. A really very good idea in fact, helped a bit by my visit last week to the factories that make high speed AC motors and inverters that drive them.
well hey... I thought the ignition/starting thing was funny. I like the idea of green too. I don't see tesla as green. the tech isn't there yet. and if you've been on this planet as long as I have... you know there is NOTHING revolutionary about induction motors (circa 1889) or lithium batteries(circa 1979)... I don't like the idea of highly subsidized innovation. If products can't stand on their own... forcing them down the consumers throat doesn't make them better.
I know all that. I don't agree with the original comment, and was not defending it. I was defending the right of its author to have his comment seen and discussed.
I disagree on the downvoting response to the comment. The answer to a flawed argument shouldn't be downvoting. The answer should be a dismantling of the assumptions and the argument.
Downvoting is a tool for silencing a comment. Some comments should be silenced. Trolls, childish behaviours, one-liners should all be silenced. Generically, stuff that does not lead to a productive discussion.
I know many people genuinely believe the stuff written on the comment I was referring to. This is not a comment that should be silenced. Better than silencing the guy through downvotes would be to correct him and enlighten all those who believe electric motors require oil changes.
> Are there voting guidelines for HN? Am I in the wrong here?
There aren't formal guidelines. The informal practice has always been that downvoting for disagreement is ok, but when people see a comment that has been downvoted unfairly, they upvote it back to par.
We're open to changing that, but we look at the data pretty closely and the current balance strikes me as about right. We can't read all the comments, though. If you see a comment that has clearly been unfairly downvoted (i.e. is faded out when it shouldn't be), please tell us about it at hn@ycombinator.com. If there get to be very many of these, we'll start thinking about how to change that.
Should a motor fail. The cost is significant.
I like the idea of an electric car, but the truth is the motors do fail. They require maintenance in the static environment of a factory or they will fail, a car on the open road with harsh environmental factors it will be hard on them.
But the biggest lie about electric car maintenance is that is lower. Its not. 90% of a vehicle's maintenance has nothing to do with its motor. It's tires, brakes, lighting, lubricants(yes electric motors need oil changes too), and power systems. Which I suspect will be more extensive here since there will be countless OS upgrades to both the drive systems and the power control units.
Its not possible at this time to compare gas engine maintenance w/ electric motor maintenance because its not apples to apples. You can however look at replacement cost as an indication of serviceability. A 400hp electric motor costs about $24,000 vs. a 400hp gas engine at about $6000.
The gas engine is still far more economical at this point even factoring in fuel costs.