Featured Lexus RZ is selling $13,000 below MSRP in Southern California due to inventory surplus

There are no eddy current loses in a Toyota permanent magnet motor?

 

iirc - tesla ditched induction motors some 3 or so years ago for permanent magnet, as they're less lossy.
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You are looking at the 5 year old models when tesla first put the second motor in front, and it actually was the same motor as in the performance model although software limited it's power. That changed at the end of 2019.

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The awd model now takes a hit of 2% in the city and 1% on the highway.

The new rwd isn't up on model Y yet on fueleconomy.gov but it is on tesla. On the Y the rwd model is about 3% more efficient, versus 11% on the 5 year old model 3. On the 2024 model Y the rwd and awd use the same battery.

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On the lexus RX the rwd is 20% more efficient than the awd. Still Toyota can look at what tesla did and make some big improvements in dual motor efficiency.

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The 2022 prime is slightly more efficient than the tesla 3, but it likely comes down to tires for city and efficiency of drivetrain for highway. The model 3 has much higher rolling resistance in its tires. Both have about the same aerodynamics but the tesla motors are likely more efficient at highway speeds which lets face it you can't do for too long in the previous generation prime so not a dig.
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On the new prius prime the model 3 is more efficient. The se prime with 17" wheels and tires, more efficient than the higher trim prius primes with 19" wheels and tires.

YMMV depending on how you drive.

The model 3/Y AWD use a rear pm motor, and a front induction motor. The model S/X used to use 2 induction motors but now use pm motors on front and rear with the plaid getting 3 motors - one for the front axle and one for each rear wheel.

 

From what I've read, both the rear motor in a Tesla and the motors in Toyota's vehicles are a permanent magnent reluctance motor hybrid. This is how they get great efficienices and torques at low RPMs and high RPMs, so over the whole range, as the rotor's angle compared to the rotating field changes from low RPM to high RPM, making it effectively a PM motor only at low RPM and a reluctance motor at high RPM. This disign is actually something I both love and hate, because it is an ingenius design but also is the final nail in the coffin for a real two or three speed manual transmission in an EV.

 

The concern over rare earth mineral supply and cost also lessened.

 

I have a solution!

Ditch pemanent magenets. They require rare earth metals so aren't good.

Just use synchronous reluctance motors. These have a narrow torque and efficiency band, but also don't have the eddy current, inefficiency problem induction motors have because they are synchronous, the rotor spins the same speed as the rotating field, and the rotor is cheap iron, nothing more.

As a plus, they need transmissions. That way I can get my 5 speed EV stick shift commuter car.

Thank you for your attention to my armchair engineering.

 

are you trying to kill the electric car?

 

I'm hoping for an electric car that I meets all my preferrences, I guess because what I like and want nobody else does.

• FWD EV sedan.
• With stick shift.
• Doesn't need more than say 50hp or even 30hp.
• Has a tow rating.
• Has a spare tire.
• Has a metal roof and flatish metal trunk lid (for ham radio antennas).
• Ownership costs comparible to the dying econocar (back in the day, the air-cooled VW Beetle, the Geo Metro, and more recently the Honda Fit, Toyota Yaris, Mitsubishi Mirage, Nissan Versa, Chevy Spark, etc.)
• Personally I don't care if it has ultra fast charging. But enough battery capacity to be sure I can make it to the next charging station even in winter would be great.

Glass roofed/sun roofed, RWD/AWD crossovers with single speed gears and ludicruos acceleration and such are nice, but just not at all what I'm interested in.

 

yeah, there isn't a car or politician in the universe that meets all my preferences. i even had to compromise on mrs b

 

Tesla's reason for using induction motors was from the valid concern over rare earth element supplies and prices. Those became less volatile in time, so they switched to a permanent magnet motor. An induction motor doesn't have a magnetic field when de-energized, thus no braking effect at that time. Eddy current brake - Wikipedia Which is why Tesla continued to use an induction motor for the secondary one in AWD drive trains.

Rare earth mineral cost and supply are still a concern. It's why the gen2 Volt had an iron magnet in one of its motors, and why Honda and others are developing motors to reduce the amount of the minerals, or eliminate them.

 

The problem with EV's is, in a way, you kind of need best performance and efficiency. A few percent of efficiency gains or losses in an EV make a pretty big deal to the consumer. Most consumers want EV's that have a 500+ mile range, so squeezing out every last mile possible is pretty important for EV manufacturers.

In an ICE you might get a bit more power or efficiency if you use a copper berilium mix for valve seats, or magnesium alloy blocks with yittrium and other such minerals to slightly outperform alluminum. But in the end, getting 50mpg compared to 40mpg or even 30mpg in an ICE isn't that big of a deal to your average consumer. So the question becomes, what's the point? I guess ICE's have expensive minerals in the catalytic converters, so that could be comparible. But in an ICE you have to have those catalytic converter minerals anyway, whereas in an EV those rare, expensive, and controversial minerals are optional.

 

Electric motors have stators made of many plates. The thinner the plate, the harder it is to induce eddy currents. However, with permanent magnetic motors there will always be some eddy current drag. It may be very small, but it will still be there.

On the other hand there are bigger fish to fry, and permanent magnet motors offer better efficiencies over all.

I'm afraid that Aptera is on the brink of beating Toyota in the efficiency race. Aptera may end up like the Geo Metro, something that's very efficient but nobody wants. The 1994 Geo Metro xfi got 43 mpg/city and 52 mpg/highway (new adjusted ratings) long before the Prius even came out and better than the Gen 1 Prius too both city and highway. Mind you that the 1994 Metro xfi would cost just over some $15,000 in today's dollars, so apples to oranges. EV's are expensive, so are hybrids. Now I want to find and fix up a 1994 Geo Metro xfi.

 

AWD will always be less efficient (by how much is the question) and also costs more (more parts). It does make me sad, since the EV craze is threatening the affordable FWD. I guess we're supposed to choose now between RWD (not the greatest for snow and ice because you can't point your powered wheels) and AWD (more expensive, and cars are already too expensive) kind of like back when I was young.

Interesting comparison. The cheapest used Tesla on the Cars.com is a 2015 Model S for $10k. Sadly the cheapest full coverage insurance on a Model S would not work for me as it would be some $400 per month.

The cheapest non-S or X Tesla that I found is a 2022 Model 3 for $15k. The last time I had an insurance quote for a similar vehicle it was around $190 per month.

In comparison, I just got a quote from Progressive and the insurance an a 1994 Geo Metro would around $30 per month. Of course that's just liability, but you don't need full coverage on a car that's not worth more than the deductible.

But even at 40+ mpg, the Tesla is enticing to me in comparison. I'm just a bit afraid of longevity at 150k miles and have a few qualms for now, but if my Toyota Avalon were stolen tomorrow, I'd consider the Tesla.

The cheapest BZ4X I could find is a tiny bit less than $25k. I have no idea what the insurance would be for me on it.

I highly doubt I could afford a Lexus RZ, even with the price cuts.

 

Our nearby dealership has 42 BZ4X, plus 6 trucks and a Venza. That’s it.

 

Canada has an allocation problem, just not getting enough from the factory located therein.

I was into my local small town dealer this week and surprised at the number of cars on the lot. Didn't stay long enough to do the count but there were lots of Rav4s. No idea of the hybrid or plug in counts.

 

What Toyota are you comparing the Y too?
The Model Y AWD suffers a 4.65% reduction in efficiency compared to the RWD.
The bZ4X is a 12.6% loss compared-.
The RZ is a 7.2%.

Part of the problem for RWD in poor conditions in the past was that more of the car's weight is in the front. Generally not a problem with a BEV. Then vehicle stability control and other advances helped a lot in countering the downsides in driving in those conditions. The manufacturers stuck with FWD in ICE cars for the first place, meeting fuel efficiency targets.