CT Use of rare earth magnets

[Tinker71]

I always wondered why the RWD single motor CT had a range of 250 miles while the dual motor had a range of 300 miles. While the easy answer is a slightly larger battery pack, could it be that one of the motors in the CT2 is a permanent magnet motor and it is more efficient. Like Tesla does with the model 3?

Rare earth magnets

There are several folks that are hypothesizing that Tesla will go to direct drive with either 2 motors in the rear, or 4 motors, 1 at each wheel.

If Tesla uses the plaid motor then there are 4 motors requiring rare earth magnets. If they use induction motors it will be less efficient.

I suppose you could put 2 PM magnets up front or rear and still have the efficiency like the Model 3.

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[Crissa]

Different motors get you different efficiency and power bands, which is what Tesla is doing. Saves on the need for a complex transmission.

The original three models were arranged each to optimize price, efficiency, and power. Capability increases between them.

-Crissa

 

[Tinker71]

Different motors get you different efficiency and power bands, which is what Tesla is doing. Saves on the need for a complex transmission.

The original three models were arranged each to optimize price, efficiency, and power. Capability increases between them.

-Crissa

Any idea what they will do with a quad motor?

 

[TheLastStarfighter]

Any thoughts and answers on the range difference is really just speculation. We don’t know the battery sizes. I would suspect their initial plan involved more battery for the CT2, but I think all plans have changed. And that is, of course, my own baseless speculation.

 

[Crissa]

Any idea what they will do with a quad motor?

That seems to drop into the spot for 'performance'.

My theory is that Tesla, once they'd committed to the four-wheel steering, will have basically made motors that slot in fore and aft, fairly ambidextrously.

They'd still need a PM and Induction pair for the Dual-motor, but they had been crossing the streams of Semi (which used induction motors) and Model S (Plaid). So I have no idea.

I don't know if they'll make an induction pair for the front or not; it depends on whether that part can be used elsewhere or not. It's just so hard to know.

I just know it's Tesla's standard affair to have a 'performance', 'efficiency', and 'budget' selection, of which often only two are available at any time (depending upon factory availability, basically.)

It's all up in the air. Which parts are cheaper to duplicate, which ones might see use elsewhere in their line, etc. I expect we'll see single, dual, quad; but we might end up with dual, quad, and quad.

-Crissa

 

[JBee]

Any idea what they will do with a quad motor?

All PM if they use the Plaid/M3 motor.

But, if they achieve their 4680 price target, drivettain efficiency will play a secondary role to achieve desired range. You just add a few more cells to overcome the extra energy losses from the motor, at some point when batteries are cheap enough they might swap back to induction. Having 4 motors also means they won't need to milk more power from the motors for accelerating the heavier CT.

After seeing the plaid motor teardown I am less impressed with the Plaid drivetrain overall, and see it more as an incremental improvement over the M3, seeing that it is mostly "just" a new rotor design. It would be interesting to see where the plaid motors are at all in a efficiency comparison. For example what does the MS LR use?

 

[Dids]

All PM if they use the Plaid/M3 motor.

But, if they achieve their 4680 price target, drivettain efficiency will play a secondary role to achieve desired range. You just add a few more cells to overcome the extra energy losses from the motor, at some point when batteries are cheap enough they might swap back to induction. Having 4 motors also means they won't need to milk more power from the motors for accelerating the heavier CT.

After seeing the plaid motor teardown I am less impressed with the Plaid drivetrain overall, and see it more as an incremental improvement over the M3, seeing that it is mostly "just" a new rotor design. It would be interesting to see where the plaid motors are at all in a efficiency comparison. For example what does the MS LR use?

I guess when you watched the teardown you missed the duel rear motors.... but yes incremental... like sucking on a straw vs a garden hose is incrementally more

 

[Dids]

There is another variable that increases range other than motors or cell count. On battery day 4680 was presented with 3 chemistry. Assume no lfp for CT. That leaves standard range versions with current chemistry and the CT3 long range using high nickel chemistry.... I am guessing that the current production 4680 are not the high nickel chemistry thus the delay on semi and CT. Instead a Quad motor CT using plaid model S rear duel motor front and back with a standard range 4680 pack will be produced first.... I expect CT4 in the 300mile range.

 

[Ogre]

People underestimate the value of continuous incremental improvement. Each little bit, particularly in a system like the Cybertruck is additive. The performance benefits of the Plaid drivetrain plus the benefits of the 4680, plus the benefits of the front/ rear Gigacasting, plus the new benefits from whatever improvements they make for the Cybertruck specifically… it ends up with a pretty huge difference from the Model 3 which is just a few years old.

Even the 4680 cells themselves are a collection of “incremental“ improvements. A small improvement to energy density, some more improvements to energy density due to the fact that it’s structural, plus a dozen other changes. None of those changes are huge by themselves, but since Tesla rolled them all up together it turns into a monumental change.

The Cybertruck and the next gen Model Y are the culmination of a giant pile of incremental changes.

 

[JBee]

I guess when you watched the teardown you missed the duel rear motors.... but yes incremental... like sucking on a straw vs a garden hose is incrementally more

Dual motors is what they already have on semi right? So how is that not like sucking on two straws? Or do two motors duel with a hose for some reason? ?

There's plenty of EV's with more than one motor, to be honest I'm surprised it took Tesla this long to get to a CT4 design, it's been on the list since the term hypercars was invented last millennia. Been talking about it here since 2019 too as to why. Same with 4WS.

Less impressed doesn't mean I'm not impressed btw, just less after I saw the differences for myself in the teardown.
To be honest I was hoping for a next gen induction motor. They need to at least look at radial flux and chorus motor inverter and see if they can't get rid of more of the bearings and gears to make it more of a direct drive, especially so if they have 4 motors to extract power/torque from. One comes with the other.

 

[Ogre]

I think Tesla wanted to drop 4680s into the rebooted Model S and the Model X which is why they were delayed so much. Eventually, the delays to the 4680 made them push out something which wasn’t as huge a step up as they had planned.

 

[charliemagpie]

Like watching grass grow... or water boil.

Those who are at the front of the waiting list, a delay is instantly disappointing. The exact timing is topical for them.

I am 900,000 on the waiting list. I ordered a tri-motor, which is 40% of the orders. We guessed the Tri is first built. So I may be 400,000th in line, Woopie !.

So I have to HOPEFULLY wait 24-36 months ... that's my guess. Moral of the story... Since my wait is that long, 6 months here or there... Same thing.

Just my AU 2 cents, which is 1.45 cents to most of you.

 

[flowerlandfilms]

Like watching grass grow... or water boil.

Those who are at the front of the waiting list, a delay is instantly disappointing. The exact timing is topical for them.

I am 900,000 on the waiting list. I ordered a tri-motor, which is 40% of the orders. We guessed the Tri is first built. So I may be 400,000th in line, Woopie !.

So I have to HOPEFULLY wait 24-36 months ... that's my guess. Moral of the story... Since my wait is that long, 6 months here or there... Same thing.

Just my AU 2 cents, which is 1.45 cents to most of you.

I'm hoping all the Australian ones come on one ship so those at the back of the list get them at the same time as those at the front, whenever that will be.

 

[Tinker71]

I'm hoping all the Australian ones come on one ship so those at the back of the list get them at the same time as those at the front, whenever that will be.

Well that it just spiteful. I suspect they will dribble in with the shipments of S3XY and your plan for Australian egalitarianism will be foiled.

 

[JBee]

I'm hoping all the Australian ones come on one ship so those at the back of the list get them at the same time as those at the front, whenever that will be.

I hope not! I have one in the low 40k, and three more after that.

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