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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 y

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.

mikeash 13y ago
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.
- 001sky 13y ago
  http://media.caranddriver.com/images/media/51/under-the-teslas-skin-2013-tesla-model-s-january-2013-issue-large-photo-493014-s-original.jpg http://media.caranddriver.com/images/media/51/under-the-tesl... 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.
  - mikeash 13y ago
    That's nice, but I'm specifically wondering about the motor "oil changes" and the cost of the motor itself, and this doesn't address that at all.
    - 001sky 13y ago
      What's your theory on how they lubricate the spinning parts?
      - mikeash 13y ago
        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.
      - Jack000 13y ago
        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.
        deleted 13y ago
        [deleted]
    - Avshalom 13y ago
      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.
jesusmichael 13y ago
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.
- hatbert 13y ago
  Have you tried looking for motors that aren't designed for 60 Hz operation? I think you might be in for a surprise...
  - jesusmichael 13y ago
    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...
- leoedin 13y ago
  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.
  - revelation 13y ago
    And then you factor in that Tesla produces the majority of the motor in house from raw materials.
pravda 13y ago
>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.
- jamesaguilar 13y ago
  > I'd say you are off by an order of magnitude. 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.
  - letstryagain 13y ago
    The entire car is only about twice that, and we know the battery is very expensive. There's no way the electric motor costs $24k.
    - jesusmichael 13y ago
      Here's one on Ebay for $10k.. Ebay! http://www.ebay.com/bhp/300-hp-electric-motor http://www.ebay.com/bhp/300-hp-electric-motor General Purpose 350HP motor. $25K http://www.globalindustrial.com/p/motors/ac-motors-2-phase/3-phase-general-purpose-motors/baldor-motor-m44354t-4-350-hp-1785-rpm http://www.globalindustrial.com/p/motors/ac-motors-2-phase/3... In general these motors have tight tolerances and aren't the motors in your electric shaver The entire car cost $70K...
      - D_Alex 13y ago
sergiosgc 13y ago
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?
- D_Alex 13y ago
  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.
  - sergiosgc 13y ago
    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.
    - mikeash 13y ago
      A sufficiently bad argument becomes a troll. There's no clear dividing line.
mehrdada 13y ago
> yes electric motors need oil changes too "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.
- chrisBob 13y ago
  I agree, people should think of an electric motor oil change more like changing transmission fluid or gear oil than a 3k mile oil change.
- jesusmichael 13y ago
  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.

mikeash 13y ago

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.

001sky 13y ago
http://media.caranddriver.com/images/media/51/under-the-teslas-skin-2013-tesla-model-s-january-2013-issue-large-photo-493014-s-original.jpg http://media.caranddriver.com/images/media/51/under-the-tesl... 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.
- mikeash 13y ago
  That's nice, but I'm specifically wondering about the motor "oil changes" and the cost of the motor itself, and this doesn't address that at all.
  - 001sky 13y ago
    What's your theory on how they lubricate the spinning parts?
    - mikeash 13y ago
      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.
    - Jack000 13y ago
      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.
      - deleted 13y ago
        [deleted]
  - Avshalom 13y ago
    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.

jesusmichael 13y ago

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.

hatbert 13y ago
Have you tried looking for motors that aren't designed for 60 Hz operation? I think you might be in for a surprise...
- jesusmichael 13y ago
  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...
leoedin 13y ago
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.
- revelation 13y ago
  And then you factor in that Tesla produces the majority of the motor in house from raw materials.

pravda 13y ago

>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.

jamesaguilar 13y ago
> I'd say you are off by an order of magnitude. 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.
- letstryagain 13y ago
  The entire car is only about twice that, and we know the battery is very expensive. There's no way the electric motor costs $24k.
  - jesusmichael 13y ago
    Here's one on Ebay for $10k.. Ebay! http://www.ebay.com/bhp/300-hp-electric-motor http://www.ebay.com/bhp/300-hp-electric-motor General Purpose 350HP motor. $25K http://www.globalindustrial.com/p/motors/ac-motors-2-phase/3-phase-general-purpose-motors/baldor-motor-m44354t-4-350-hp-1785-rpm http://www.globalindustrial.com/p/motors/ac-motors-2-phase/3... In general these motors have tight tolerances and aren't the motors in your electric shaver The entire car cost $70K...
    - D_Alex 13y ago

sergiosgc 13y ago

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?

D_Alex 13y ago
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.
- sergiosgc 13y ago
  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.
  - mikeash 13y ago
    A sufficiently bad argument becomes a troll. There's no clear dividing line.

mehrdada 13y ago

> yes electric motors need oil changes too "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.

chrisBob 13y ago
I agree, people should think of an electric motor oil change more like changing transmission fluid or gear oil than a 3k mile oil change.
jesusmichael 13y ago
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.