5.0 miles/kWh: Say Hello to the World's Most Efficient Car

[BS8899]

From my understanding PM motors are not for performance applications. There is a delay in pushing power through them. I wouldn’t expect PMMs in a Sapphire like car anytime soon. I think Tesla dual motor performance cars use one permanent magnet rear motor and an induction front motor to kind of balance out the responsiveness with efficiency

Consistent with my understanding. I think a "hybrid" architecture in a multi-motor car is a good way to balance.

 

[borski]

I don't want to debate @Bunnylebowski's point of view. Rather, I like us all to be educated on the 5 mile/kWh milestone and applicability.

I do have a few questions in terms of the applicability of this technology across Lucid's product line and for EVs in general:

> the high efficiency, at 5 miles/kWh, was achieved on the Lucid Pure, correct?
> the efficiency/range gain is ~8%, correct?
> this instantiation uses a single PMSM, correct?
> the other Lucid trims use induction motors, correct?
> Are PMSMs more costly to manufacture?
> are there practical limitations to scaling up the size/power of PMSM? Specifically, can the AGT/Sapphire be one-day equipped with multiple PMSMs? Cost/space impact?
>alternately, is PMSM more applicable to certain EV segments, e.g., medium performance EVs?
> some other EV manufacturers also use PMSMs, correct? How do they compare to Lucid's Pure PMSM implementation?
> (forgive my ignorance) If I understood correctly, the (original) Rivian R1S quad motor also use PMSM motors (4X). This architecture enables Rivian's "Conserve" mode that improves the mileage/efficiency (by shutting down the two rear motors). My experience is, this "Conserve" mode extends the range by ~7-8% on the R1S.

Lucid only uses PMSM motors:

 

[BS8899]

Lucid only uses PMSM motors:

Ummm, interesting.

A while, I posted a question RE: why can't Lucid enable a "Conserve mode" similar to Rivian. A member responded that Lucid can't, because it uses induction motors. Was that incorrect?

If so, let me re-post the question....why can't Lucid implement a "Conserve mode" to get more efficiency similar to what Rivian did?

 

[Adnillien]

Ummm, interesting.

A while, I posted a question RE: why can't Lucid enable a "Conserve mode" similar to Rivian. A member responded that Lucid can't, because it uses induction motors. Was that incorrect?

If so, let me re-post the question....why can't Lucid implement a "Conserve mode" to get more efficiency similar to what Rivian did?

According to Eric Bach, it is automatically engaged when at highway speed below 85 mph and not rapidly accelerating. Maybe Lucid beats Rivian for this case.

 

[xponents]

According to Eric Bach, it is automatically engaged when at highway speed below 85 mph and not rapidly accelerating. Maybe Lucid beats Rivian for this case.

I would like to ask another question: Is there a reason these companies disable the rear motor(s) instead of the front? This would give it RWD driving dynamics and theoretically save the same amount of energy compared to a front motor only setup. Is it because regen is more effective on the front?

 

[Bunnylebowski]

Yeah if you want to conserve more shut off climate. I’ll be honest I don’t think I’ve ever been in a situation in the Lucid where I needed to conserve range even more than the range the car gets. I don’t anticipate that in the future either unless there’s like a week long blackout or something. What’s effective though at improving efficiency is taking as long as you can to slow down when slowing as you spend more time in regen.

 

[momo3605]

Ummm, interesting.

A while, I posted a question RE: why can't Lucid enable a "Conserve mode" similar to Rivian. A member responded that Lucid can't, because it uses induction motors. Was that incorrect?

If so, let me re-post the question....why can't Lucid implement a "Conserve mode" to get more efficiency similar to what Rivian did?

Ok I just did a little bit of googling on the topic. Turns out permanent magnet motors are the ones that CANT be switched off. Rivian and lucid both use PMM, but Rivian has a physical disconnect for the rear axle. This is noticeable in my Rivian because you feel a loud clunk when switching in and out of Conserve.

Lucid doesn’t have a physical disconnect. There is no “conserve” equivalent in a Lucid

 

[xponents]

Ok I just did a little bit of googling on the topic. Turns out permanent magnet motors are the ones that CANT be switched off. Rivian and lucid both use PMM, but Rivian has a physical disconnect for the rear axle. This is noticeable in my Rivian because you feel a loud clunk when switching in and out of Conserve

This is the correct answer. I believe only induction motors can turn off without a physical disconnect.

 

[momo3605]

I would like to ask another question: Is there a reason these companies disable the rear motor(s) instead of the front? This would give it RWD driving dynamics and theoretically save the same amount of energy compared to a front motor only setup. Is it because regen is more effective on the front?

I would venture to guess it may be safety related? I’ve driven a Dodge Ram that has part time AWD, and by default they are in RWD, in a little bit of rain, and it was spinning out. Especially in high torque applications like EVs. BMW AWD M cars I know have a RWD mode. But I can’t think of EVs other than Rivian that can disconnect 2 wheels

 

[DeaneG]

I would venture to guess it may be safety related? I’ve driven a Dodge Ram that has part time AWD, and by default they are in RWD, in a little bit of rain, and it was spinning out. Especially in high torque applications like EVs. BMW AWD M cars I know have a RWD mode. But I can’t think of EVs other than Rivian that can disconnect 2 wheels

Some Kia/Hyundai EVs have a front motor clutch, with a rear clutch unit on the coming Polestar 3, off the top of my head.

 

[BS8899]

Ok I just did a little bit of googling on the topic. Turns out permanent magnet motors are the ones that CANT be switched off. Rivian and lucid both use PMM, but Rivian has a physical disconnect for the rear axle. This is noticeable in my Rivian because you feel a loud clunk when switching in and out of Conserve.

Lucid doesn’t have a physical disconnect. There is no “conserve” equivalent in a Lucid

I presume, PM motors can be "switched off". But, without a physical disconnect, the rotors will still rotate. That becomes a "generator"?

Presumably, a physical disconnect is necessary to prevent to PM motor turning into a "generator"?

 

[Sam6062]

Furthermore, DreamDrive Pro is now only 2500 dollars on top of the standard premium. Lucid evolving and listening to almost everybody's feedback here on the forum is fantastic, as the price of these options have been commonly talked about here. The Pro system is now a bargain, at least to me!

Some other changes not mentioned in the press release that I spotted in the configurator:

The Mojave PurLuxe interior now has the fabric headliner that was originally standard for 2022 Pures (none were actually delivered, but Alcantara was an 800 dollar option for the very first owners).

Any leather interior has the same finishes as the GT did previously, with Alcantara on the dash/doors (where on Tourings and leather-equipped Pures, it was "full grain leather").

The volume knob as well as the dials on the steering wheel appear to have a bronze-like finish on Purluxe interiors, although I'm betting this is a rendering error.

Maybe they will give us a generous discount for being early adopters of the 2022 model

 

[Steveinarizona]

Ok I just did a little bit of googling on the topic. Turns out permanent magnet motors are the ones that CANT be switched off. Rivian and lucid both use PMM, but Rivian has a physical disconnect for the rear axle. This is noticeable in my Rivian because you feel a loud clunk when switching in and out of Conserve.

Lucid doesn’t have a physical disconnect. There is no “conserve” equivalent in a Lucid

My Genesis GV60 performance has two PMSMs, one on each axle. I have read that in several locations but had to go to a Chinese web site to get official confirmation from Genesis:

GENESIS GV60 - Spec | GENESIS CHINA

www.genesis.com.cn

But my GV60P is rear wheel biased. I have a "power distribution widget" that shows, graphically, which wheels are being powered and to what extent. When I accelerate I see all wheels being powered; but most of the rest of the time it is only the rear wheels. The change from RWD to AWD and back is totally seamless...no "clunk".

I do not claim to be an expert and can't explain why this is so but it is.

 

[DeaneG]

I presume, PM motors can be "switched off". But, without a physical disconnect, the rotors will still rotate. That becomes a "generator"?

Presumably, a physical disconnect is necessary to prevent to PM motor turning into a "generator"?

PM motors do work as a generator (actually an alternator) when driven. This is how regeneration works. Power generated by the motor is used to charge the battery.

Opening the PM motor's semiconductor drive switches (the main element in the inverter) disconnect the drive motor electrically from the rest of the car. These switches are the same six semiconductors that turn the battery's DC voltage into AC to operate the motor. The switches work bidirectionally. They can send power from the battery to the motor, or send power from the motor back to the battery.

With the motor's drive switches turned off, the motor's rotor then spins freely, except that spinning the rotor creates a rotating magnetic field in the motor's stator. The rotating magnetic field causes losses in the stator's ferrous elements (the steel laminations). Losses may be in the few percent of maximum torque range depending on the design of the motor. These losses present a counter-torque at the motor shaft. It feels like a frictional drag if you are the one spinning the motor. Adding a mechanical clutch to prevent the PM motor from spinning when idle eliminates this friction when the motor's output isn't needed.

Induction motors do not need a clutch as their magnetic field is de-energized when not in use, so motor losses are very low - about the same as spinning a shaft and reduction gear alone.

 

[xponents]

My Genesis GV60 performance has two PMSMs, one on each axle. I have read that in several locations but had to go to a Chinese web site to get official confirmation from Genesis:

GENESIS GV60 - Spec | GENESIS CHINA

www.genesis.com.cn

But my GV60P is rear wheel biased. I have a "power distribution widget" that shows, graphically, which wheels are being powered and to what extent. When I accelerate I see all wheels being powered; but most of the rest of the time it is only the rear wheels. The change from RWD to AWD and back is totally seamless...no "clunk".

I do not claim to be an expert and can't explain why this is so but it is.

Steve, our EV9 also disables the front motor and powers the rear wheels with its "eco" mode (we have the same power distribution widget). There is also no clunk in our case. Could somebody explain how this is?

 

[AirBo]

"The new Lucid Air Pure delivers 420 miles of EPA-estimated range from a battery pack that is just 84 kilowatt-hours. Enabled by further advancements of Lucid’s groundbreaking technology, this makes the Lucid Air the first vehicle in the world to achieve a ratio of 5.0 miles of range per kilowatt hour (kWh) of energy."

5.0 miles/kWh: Say Hello to the World's Most Efficient Car

lucidmotors.com

It is frustrating to learn that GT owners not only overpaid (new car is now cheaper by $40 000 or more) for their cars and were the pioneers and test drivers for Lucid and yet improvements are only on Pure cars. Is there an improvement for other Lucid cars?

 

[AirDoll]

It is frustrating to learn that GT owners not only overpaid (new car is now cheaper by $40 000 or more) for their cars and were the pioneers and test drivers for Lucid and yet improvements are only on Pure cars. Is there an improvement for other Lucid cars?

A GT fully loaded with everything we got included is definitely not that much less expensive now once you add those features. I find nothing “frustrating” about the price I paid for what I got and when I got it. We are not “test drivers”, we knew exactly what we were getting. Zero regrets.

 

[xponents]

It is frustrating to learn that GT owners not only overpaid (new car is now cheaper by $40 000 or more) for their cars and were the pioneers and test drivers for Lucid and yet improvements are only on Pure cars. Is there an improvement for other Lucid cars?

You were fine with the price when you bought it, but okay. Also, your bio shows you have a Touring. Are you seriously getting angry on the behalf of OTHER people? This is hilarious...

 

[hydbob]

It is frustrating to learn that GT owners not only overpaid (new car is now cheaper by $40 000 or more) for their cars and were the pioneers and test drivers for Lucid and yet improvements are only on Pure cars. Is there an improvement for other Lucid cars?

At least they weren't idiots like those Dream Edition buyers...man what dummies

 

[xponents]

At least they weren't idiots like those Dream Edition buyers...man what dummies

Or the Sapphire buyers who overpaid for getting a glass roof removed and 100 more HP... even dumber of them