model 3 weight vs performance

[Twiglett]

I wouldn't be surprised if the base RWD 3 was motor-limited, not battery-limited, for power. That would give all RWD variants roughly the same 0-60 times.

that wouldn't make sense. They know they will be constantly improving battery capabilities, why would they deliberately make the motors less powerful.
Electric motors aren't like ICE where extracting power is difficult and expensive. Its just difficult, they aren't saving huge amounts of money shaving the power capability of the motor.
Much more likely to stay battery limited so they can continue to grow the car over time.
[edit]
Remember the benchmark cars mentioned.
Add that they will want to crush the capabilities of the Bolt, not just beat it slightly
In Elon's words "We don't make slow cars"

 

[R.S]

that wouldn't make sense. They know they will be constantly improving battery capabilities, why would they deliberately make the motors less powerful.
Electric motors aren't like ICE where extracting power is difficult and expensive. Its just difficult, they aren't saving huge amounts of money shaving the power capability of the motor.
Much more likely to stay battery limited so they can continue to grow the car over time.
[edit]
Remember the benchmark cars mentioned.
Add that they will want to crush the capabilities of the Bolt, not just beat it slightly
In Elon's words "We don't make slow cars"

I do think that the 75 might be quicker than the 55, but your reasoning doesn't make sense. A motor and inverter still costs money. And the more power, the more money you'll spend. So with decreasing battery costs and decreasing overall vehicle costs, the influence the motor/inverter has over total production costs increases.

I'd argue differently. Tesla is in a situation right now to come up with new motors for their whole product line and save costs. And with the volume the Model 3 brings, 3-5 motors for all Tesla vehicles could definitely make sense. Because at some point, economics of scale doesn't really help as much as saving on each piece, by using 2 different solutions.

I also think it's possible that all Model S/X versions will get quicker, because of those new motors.

 

[Twiglett]

I do think that the 75 might be quicker than the 55, but your reasoning doesn't make sense. A motor and inverter still costs money. And the more power, the more money you'll spend. So with decreasing battery costs and decreasing overall vehicle costs, the influence the motor/inverter has over total production costs increases.

I'd argue differently. Tesla is in a situation right now to come up with new motors for their whole product line and save costs. And with the volume the Model 3 brings, 3-5 motors for all Tesla vehicles could definitely make sense. Because at some point, economics of scale doesn't really help as much as saving on each piece, by using 2 different solutions.

I also think it's possible that all Model S/X versions will get quicker, because of those new motors.

Take a look how much cost an extra wind or two will add to the Model 3, maybe $2 if that. Thats all it takes to increase performance with a motor. The vast majority of their cost savings will come from reducing people time not material cost.
Tesla makes fast cars - period. The chances of the Bolt being faster are zero, Elon will not let GM "out EV" any aspect of the Model 3.

 

[R.S]

Take a look how much cost an extra wind or two will add to the Model 3, maybe $2 if that. Thats all it takes to increase performance with a motor. The vast majority of their cost savings will come from reducing people time not material cost.
Tesla makes fast cars - period. The chances of the Bolt being faster are zero, Elon will not let GM "out EV" any aspect of the Model 3.

You think they would omit windings in a motor, so they can create a more powerful version later? Otherwise your comment doesn't make any sense. You can't just increase the copper fill, just because you like to. You could have the motor windings filled in by hand, but that would be way more expensive.

The simplest solution to make an induction motor more powerful, without coming up with a totally new motor, would be switching to a copper cage, which will increase manufacturing and materials cost.

 

[Twiglett]

You think they would omit windings in a motor, so they can create a more powerful version later? Otherwise your comment doesn't make any sense. You can't just increase the copper fill, just because you like to. You could have the motor windings filled in by hand, but that would be way more expensive.

The simplest solution to make an induction motor more powerful, without coming up with a totally new motor, would be switching to a copper cage, which will increase manufacturing and materials cost.

Wow - you say I don't make sense?
I expect it from me, but its strange seeing other people making no sense as well
Unless I missed something, your original point was that they would not maintain performance so they could cut costs - more power = more money (you said)
My point is that EV motors don't need to be expensive to be "performance" and the incremental difference in cost is tiny.
Therefore - as Tesla is a performance car maker they would not skimp on the motor to save a few pennies.

I almost always never make sense, hopefully this exceeds even my expectations, however if it starts to make sense, best reread it, it was probably unintentional.

 

[R.S]

Wow - you say I don't make sense?
I expect it from me, but its strange seeing other people making no sense as well
Unless I missed something, your original point was that they would not maintain performance so they could cut costs - more power = more money (you said)
My point is that EV motors don't need to be expensive to be "performance" and the incremental difference in cost is tiny.
Therefore - as Tesla is a performance car maker they would not skimp on the motor to save a few pennies.

I almost always never make sense, hopefully this exceeds even my expectations, however if it starts to make sense, best reread it, it was probably unintentional.

An EV motor and inverter get more expensive, the motor power they have. And it isn't really pennies either. A good number to estimate the costs of the inverter plus motor is $6/kW, which is rather low. So about $8 per hp. That means 100 hp more, $800 higher costs.

 

[R.S]

An EV motor and inverter get more expensive, the motor power they have. And it isn't really pennies either. A good number to estimate the costs of the inverter plus motor is $6/kW, which is rather low. So about $8 per hp. That means 100 hp more, $800 higher costs.

Edit: I messed up the conversion from kW to hp. It would be $4.5 per hp. Or $450 per 100hp more.

Still enough savings to motor limit the Model 3. A car which achieves savings, by omitting a second screen.

 

[JeffK]

Edit: I messed up the conversion from kW to hp. It would be $4.5 per hp. Or $450 per 100hp more.

Still enough savings to motor limit the Model 3. A car which achieves savings, by omitting a second screen.

Since it's an all new inverter and motor design, they might have found other ways to save money as well.

 

[R.S]

Since it's an all new inverter and motor design, they might have found other ways to save money as well.

6$/kW is already pretty optimistic. The DOE Targets for 2015 are 12 $/kW and 8 $/kW for 2020. But I think because of the new designs and the high volumes, they might still be reasonable. Even if we assume 4 $/kW, they would motor limit the vehicle.

Assuming that the new P100D, with the new cells, would be as powerful as the current one. Even a 55kW Model 3 could have about 380hp. I think they could do 0-60 in less than 6 seconds, if they had about 250hp. So Tesla could save $388, by motor limiting their vehicle, if we assume just 4 $/kW, $582 for 6 $/kW and $776, if they are just as good as the 2020 DOE target.

So I assume they will motor limit it, to achieve their price target. I just can't see them saving on screens, but wasting their money on motor power. 250 hp would make the base vehicle competitive with the BMW 330i, or the C300, and both start at about 39k. The 75 will probably get a bigger motor, to compete with the C43 and the 340i.

 

[Twiglett]

6$/kW is already pretty optimistic. The DOE Targets for 2015 are 12 $/kW and 8 $/kW for 2020. But I think because of the new designs and the high volumes, they might still be reasonable. Even if we assume 4 $/kW, they would motor limit the vehicle.

Assuming that the new P100D, with the new cells, would be as powerful as the current one. Even a 55kW Model 3 could have about 380hp. I think they could do 0-60 in less than 6 seconds, if they had about 250hp. So Tesla could save $388, by motor limiting their vehicle, if we assume just 4 $/kW, $582 for 6 $/kW and $776, if they are just as good as the 2020 DOE target.

So I assume they will motor limit it, to achieve their price target. I just can't see them saving on screens, but wasting their money on motor power. 250 hp would make the base vehicle competitive with the BMW 330i, or the C300, and both start at about 39k. The 75 will probably get a bigger motor, to compete with the C43 and the 340i.

Hang on
So the thought is that, in order to save money, they will design and build an extra motor and inverter just for the bigger battery - on the car they are simplifying the production for?
Errrr.....

 

[Jayc]

So I assume they will motor limit it, to achieve their price target. I just can't see them saving on screens, but wasting their money on motor power.

I think Model 3 is a re-think of where to spend the money - that is right. However, simplicity of dash is probably not solely cost driven although that is a key attribute of the result.

Have a feeling we are going to get hell of a value proposition in the Model 3 - a bit like when the iphone came out, it wasn't assessed on voice quality or signal reception against its competition because the smartphone taken as a whole was in a league of its own.

 

[R.S]

Hang on
So the thought is that, in order to save money, they will design and build an extra motor and inverter just for the bigger battery - on the car they are simplifying the production for?
Errrr.....

Basically yes. The cost savings of another motor option could be huge and if you could use them in the Model S and X as well, the savings might be even bigger.

A good example is the dual motor variant. If we assume that they just have a 250hp motor and put two of those together to make a 55D, they could save $1000, or more, by just using two 150hp motors.

Easy to manufacture doesn't mean every car will be the same. Not every car will come with a 75kWh battery, or just heated and ventilated seats, even if that would be easier to manufacture, by your logic.

For the car itself it makes no difference in manufacturing, if you have 3 motors to choose from, or just one. Motor production will be more complex, but with a volume like the Model 3, the cost savings should outweigh that. Cheap manufacturing means little time on the production line, but since every Model 3 gets a motor, there will be no difference, if you had 1 or 10 motors. It isn't like wiring additional cables for illuminated door handles.

3 motors would probably be enough to do anything from the Model 3 55 to the Model X 100D. If they used 3 motors on a theoretical P100T, they could use their mass produced motors in their most expensive cars.

 

[JeffK]

Basically yes. The cost savings of another motor option could be huge and if you could use them in the Model S and X as well, the savings might be even bigger.

A good example is the dual motor variant. If we assume that they just have a 250hp motor and put two of those together to make a 55D, they could save $1000, or more, by just using two 150hp motors.

Easy to manufacture doesn't mean every car will be the same. Not every car will come with a 75kWh battery, or just heated and ventilated seats, even if that would be easier to manufacture, by your logic.

For the car itself it makes no difference in manufacturing, if you have 3 motors, or just one. Motor production will be more complex, but with a volume like the Model 3, the cost savings should outweigh that. Cheap manufacturing means little time on the production line, but since every Model 3 gets a motor, there will be no difference, if you had 1 or 10 motors. It isn't like wiring additional cables for illuminated door handles.

3 motors would probably be enough to do anything from the Model 3 55 to the Model X 100D. If they allowed 3 motors on a theoretical P100T, they could use their mass produced motors in their most expensive cars.

We already know they are using an inverter capable of around 300kW. I'm not sure why they'd purposely need to produce a lower power motor if the inverter architecture is already determined and is more than enough.

As far as I know all Teslas are capable of delivering more power than the motors can/should handle (for long periods of time). It's simply software limited.

 

[R.S]

We already know they are using an inverter capable of around 300kW. I'm not sure why they'd purposely need to produce a lower power motor if the inverter architecture is already determined and is more than enough.

As far as I know all Teslas are capable of delivering more power than the motors can/should handle (for long periods of time). It's simply software limited.

We know that their inverter architecture has a capacity of over 300kW. Which means there is more than just one type of inverter, therefore the term architecture was used.

Just imagine putting 2 300kW motors in a 55D, that would be a bit of an overkill, with 800hp of installed power. It sounds cool, but I doubt that it would really make sense, financially. If they'd do that, I doubt we would see the AWD option getting cheaper, than it is on the Model S.

 

[SageBrush]

I'm very interested in Elon's approach to optimizing and reducing manufacturing costs. I presume -- but don't know -- that a simplified product line is part of the magic so I expect to see modular car manufacturing. In that vein, a high power car would be built from multiples of the base motor. This would also mean that 'P' and 'D' go together.

Too bad for me since I would like AWD but do not care about more power.

 

[JeffK]

We know that their inverter architecture has a capacity of over 300kW. Which means there is more than just one type of inverter, therefore the term architecture was used.

Just imagine putting 2 300kW motors in a 55D, that would be a bit of an overkill, with 800hp of installed power. It sounds cool, but I doubt that it would really make sense, financially. If they'd do that, I doubt we would see the AWD option getting cheaper, than it is on the Model S.

Keep in mind that the new inverters use 25% fewer unique parts and cost less per kW than the current designs on previous Model S/X units.

If you can make cheaper inverters why not simply mass produce the same one, even if it's overkill. The motors aren't necessarily capable of 300 kW.

 

[Twiglett]

Keep in mind that the new inverters use 25% fewer unique parts and cost less per kW than the current designs on previous Model S/X units.

If you can make cheaper inverters why not simply mass produce the same one, even if it's overkill. The motors aren't necessarily capable of 300 kW.

Exactly my point. Why underspec drive components knowing that battery capacity will only increase. Make one part now that will sit unchanged for the next few years, rather than having to design, test and build a whole new set just to use a new battery capability.
Its just not the Tesla way.
It is however the GM way, which is why they will not do it.

 

[PRSIST]

Has anybody read the Wikipedia write up about the Model 3?? Tesla Model 3 - Wikipedia

Does Wikipedia answer any questions people might have?

 

[R.S]

Keep in mind that the new inverters use 25% fewer unique parts and cost less per kW than the current designs on previous Model S/X units.

If you can make cheaper inverters why not simply mass produce the same one, even if it's overkill. The motors aren't necessarily capable of 300 kW.

Your argument makes as much sense, as if they just put in a 75kWh battery in any car. Because why not simply mass produce one battery, even if it's overkill? IGBTS, filters, capacitors, etc, cost money too, you know?

 

[JeffK]

Your argument makes as much sense, as if they just put in a 75kWh battery in any car. Because why not simply mass produce one battery, even if it's overkill? IGBTS, filters, capacitors, etc, cost money too, you know?

In terms of costs it's not comparable to 15 kWh of added battery capacity. What's the cost of an extra TO-247 for example, about $1.50 I'm not so sure that kind of thing breaks the bank compared to the battery capacity which is three orders of magnitude greater cost.

If they have different inverters (and likely they will have three) it's mainly due to efficiency factors and not cost.