Tiny electric motor can produce more than 1,000 horsepower

5 days ago (supercarblondie.com)

Could lead to significant efficiency gains for EV's, because 1/4 of the motor weight means better power-to-weight ratio... a lot of things will automatically get better.

YASA was founded in 2009, a spin out from Oxford University following the PhD of founder and still CTO, Dr Tim Woolmer.

"Over the decades that followed both of these technologies were explored. But despite the potential for weight reduction, smaller size, shorter axle length and increased torque, it was the difficulty in manufacturing the axial flux technology that limited its commercial viability, because the motor could not be made by stacking laminations, as with radial machines."

"The breakthrough innovation came by segmenting the axial flux motor in discrete "pole-pieces", so the motor could be manufactured using Soft Magnetic Composite material.

SMC can be pressed at low cost into a wide variety of 3D shapes. This removed the need for the complex laminations, overcoming the major manufacturing challenge of the axial flux machine."

"In 2025, after a £12m investment, YASA opened the UK's first axial-flux super factory, in Oxfordshire.

The opening of this facility boosts YASA’s manufacturing capacity, setting new benchmarks in e-motor technology and quality, and enabling production to scale beyond 25,000 units per year."

This is awesome. Lighter motors also make electric flight more viable

  • > Could lead to significant efficiency gains for EV's, because 1/4 of the motor weight means better power-to-weight ratio... a lot of things will automatically get better.

    EV motors are already lightweight. The electric motor in a vehicle like a Tesla Model 3 already weighs less than you do. Reducing that one component by 75% would be a weight savings equivalent to about a half of a passenger.

    Not a significant efficiency improvement for vehicles that weigh over 3000lbs (or double that for many EVs).

    Every little bit helps, but this isn’t a game changer.

    • This, or a miniaturized version thereof could change the game for light electric vehicles - imagine an electric motorcycle that weighs substantially more like an electric bicycle.

      Right now it takes about 10-15lbs of motor to produce a 3KW motor for an electric bike, this motor is about 10 times that in power density afaict.

      The Livewire electric motorcycles use something like 100-200 lbs of motor to produce 1/4 as much power, 75kw, so that’s an improvement of 8-16x.

      104 replies →

    • Not a game changer but I wonder if ligher motors allow you to do things like have one motor per drive wheel, removing the need for differential gearboxes?

      Then you can do clever things with traction control without having to use the ABS system to brake the drive wheels.

      Or dramatically change the turning circle on big cars and vans. Maybe even reduce the size and weight of the braking system by taking on some of that role.

      All for the same weight budget.

      13 replies →

    • If you're putting motors in wheels, lower weight means reducing the weight/capacity of adjacent systems.

      Lighter motors for mobile robots could also be cool.

    • Nice observation that the weight isn't that much of a deal compared to batteries for electric vehicles!

      It does seem like with this advancement, and the size of these axial flux motors that maybe, all wheel drive vehicles will be the default. As well as sub 3 second acceleration, which can make vehicles safer, for example getting out of the way of an incoming object. Of course it could also make them less safe because that vast of acceleration is kind of dangerous.

      But I do wonder if the weight reduction (over 30%) of lithium sulfur batteries paired with these is really going to make a great recipe for all sorts of quiet, long lasting, powerful electric vehicles and robots!

    • Exactly. Main problem is battery energy density. Cars can drive about 20 kilometers on 1 liter of gasoline. In comparison, Tesla's 4680 cells are at about 272-296 Wh/kg and CATL's Kirin Battery at about 255 Wh/kg. A bit efficient EV often uses 200 Wh/km, so for 1 kg of battery the electric vehicle can only reach 1-2 km. An order of magnitude difference. Theoretically, batteries could go to 1000 Wh/kg some day, which would mean about 5 km per 1 kg of battery assuming all else remains equal.

      5 replies →

    • Somebody's probably already pointed this out, but in the case of motors, making them lighter can make a big difference.

      For example, by making the flywheel in a clutch lighter, you reduce the amount of torque it takes to spin the flywheel. Saving 10 pounds there is not a 10/3000lb difference.. it could be a huge percentage of total power output.

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    • I would expect that lighter motor components would potentially allow weight reduction in load bearing components. Not an advantage for SUV-type cars, but for light and ultralight vehicles it could add up to more weight saving and longer ranges.

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    • > The electric motor in a vehicle like a Tesla Model 3 already weighs less than you do. Reducing that one component by 75% would be a weight savings equivalent to about a half of a passenger.

      Of which there can be two, or even three.

    • For EVs no but it's huge for flight if it could be scaled down. Paramotors and ultralight planes are on the verge of being competitive with gas they just need a bit more energy density per pound in the system.

    • Maybe this would be good for a personal quadcopter, however the batteries weight would probably make the motor weight savings unimportant.

    • The difference is when you take into consideration rotating mass, and the distribution between the stator and rotor.

    • It drops a buck fifty per motor. That IS a game changer.

      It can make cars cheaper, or longer range, or faster, or any number of other designs based on what the manufacturer is looking for.

      But to OP's point about flight - stacking 6 Tesla motors is not an option. Stacking 6 of these YASA motors? Much less weight.

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  • I wish more people on the road realized the extent to which weight reduction improves all aspects of the driving experience... it really does compound unlike any other change that you can make to a vehicle. IMO heavy vehicles are a scam and the antithesis of the direction we should be moving.

    • I agree with you however I believe weight and safety are in a complex relationship right now, which has nothing to do with performance and handling.

      Unfortunately I feel much less safe in a Fiat 500 when a significant portion of cars in the road weigh nearly 3 tonnes and perhaps can't even see me. I suspect most people are in SUVs because they're the pragmatic trade off between safety and convenience, not because they were hoping for excellent performance.

      29 replies →

    • Weight is not the only thing that matters though. You also need to consider center of gravity and wheel base. A YJ Jeep Wrangler and a Honda Fit both weigh around 2700 lbs and they even have similar wheel bases but the driving experience between those 2 is night and day. A Honda Fit can take a turn at speed without feeling like you're going to go flying. You'll feel like you're able to flip making a turn going 20 mph in a YJ.

      This is why the first performance mod that most people put on their cars is an adjustable coil over suspension. Dropping the car down by an inch or 2 changes has just as much of an impact as shedding some weight.

      Ironically, most people put lift kits on Jeeps but that also usually comes with widening the wheel base and putting on larger wheels/tires.

      6 replies →

    • Driving Volkswagen e-up for the first time was a very unique experience to me. My brain needed to adjust that a car can be that nimble and responsive due to its small size/weight and instant torque from the electric motor.

    • I went from a 2021 Opel Mokka (4.2m long, 1350kg) to a 2024 Volvo EX30 (4.2m long, 2000kg).

      It was an absolute shock the first time I braked in the Volvo, not to mention trying to take a corner.

    • > I wish more people on the road realized the extent to which weight reduction improves all aspects of the driving experience

      This is a blanket statement and completely untrue. Good driving experience is directly correlated to TRACTION, not just weight. And traction isn't just a function of weight - it also is affected by center of gravity, friction between the wheels and the road. Traction is what gives you the perception of being in control of the car.

      I used to own two cars of the exact same model - one petrol and one diesel. The petrol is lighter in weight, about 100+ kgs lighter than the diesel variant. And the driving experience on that is slightly scary especially on roads with strong winds. In fact, it is so light that if you drive over tiny puddles or rumbles strips, the car will sway sideways. The diesel always feels more planted because it is front-heavy, thus adding more traction to the front wheels (both are FWDs). I always prefer the diesel for longer drives because of the heft and confidence it provides.

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  • > In 2025, after a £12m investment, YASA opened the UK's first axial-flux super factory, in Oxfordshire.

    It’s a little sad to me that fundamental innovations in electromechanical engineering like this get just a few million in investment, yet if this had been yet another derivative software startup with “AI” in the pitch, they’d probably have 10x+ or more investments being thrown at them.

    • Seems to me everyone wants to invest, instead, into something that can be "web scale" with low marginal cost, that is, natural monopolies. There is not enough anti-trust enforcement.

    • They should have named their company "YASAI" (pronounced as "Yes AI") and just watched the investments roll in ...

    • Welcome to the UK and its innovation hostile environment. We don't have the US culture of throwing VC money at things and seeing what sticks.

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  • But EVs are already heavy because of the battery. I suppose percentage-wise the motors don't make much of a difference (?)

    • The issue with this type of motor is that it is part of the unsprung weight since it is inside the wheel. This is probably why savings here matter a lot more (or at least in a very different way) than the battery weight.

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    • It compounds. If you have a lighter more efficient motor you need a smaller battery for the same range, that combined weight loss means you meed lighter brakes etc etc, and because the car is now lighter you size of your motor you need is less.....

      They claim, this compounding effect works out to basically double the effective weight saving from battery and motor.

      ie if you start with saving 50kg on motor, and 50kg on battery, you end up saving 200kg over all. Still only about 10% of a typical electric car.

      https://youtu.be/3qjB6GnhloY?si=yqlz7Evuyf5VaghO&t=446

      5 replies →

    • Yea that's the thing right, the battery is so very much of the weight that optimizing the other parts are "meh" at this point. What is cool is that the 600Wh/kg solid state batteries seems like they are really finally here soon :) i.e removing 200-300kg from a car in one go will be a game changer.

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  • Tesla Model Y's battery is 771 kg. The motor in Model Y weights about 45 kg, about three times as much as the motor in the article. By reducing dual motor configuration weight from 90 kg to 28 kg, we reduce total powertrain weight by 7%.

  • > Could lead to significant efficiency gains for EV's

    Not really. EV's are very heavy from non-motor weight. A Model Y weighs ~4300 lbs. A motor that is 75 lbs lighter is a 1.7% savings. That's not nothing, but I wouldn't say "significant". You can do better by swapping for fancy wheels or eliminating some of the glass roof.

    And really this is true up and down the electric vehicle world. Weight-sensitive applications are always going to be completely dominated by battery weight. Making the motor smaller just isn't going to move the needle.

    Basically this is good tech without an application, which is why it's having to tell itself with links like this.

    • It’s great anywhere you want more power but are limited by space and/or weight for performance reasons. Aerospace, e-bikes, electric race vehicles, electric motorcycles.

      But yeah, EVs seem weird except for racing reasons perhaps.

      What I can’t figure out is how they dissipate the heat - double digits kw per kg is crazy.

      6 replies →

  • Hub motors are problematic because they increase the sprung weight of the wheel, which loses more traction when hitting bumps. Dangerous while cornering or braking. Scale down a motor like this to 300 HP and you could have an amazing AWD vehicle.

    This video https://m.youtube.com/watch?v=WU9Ptibu2WQ&t=179s claims that SMC materials have much higher losses at low frequencies than laminated materials, up to around 400 HZ when they very rapidly pull ahead.

    So as the core of a step down transformer for consumer electronics, SMCs would be worse than a laminated core (stack of sheet metal pieces punched with a press, stacked and wound with the windings). But in a motor operating at 100s of rpms, no problem. And as I understand it, in high torque motors the magnetic fields pulse far more often than once per revolution because the windings are many and small, so that several can pull on the armature at any orientation.

  • This is a negligible improvement to most things about an EV. Motors are already extremely power-dense.

    There is a single exception, and it's a big one. Direct-drive, wheel-hub motors are not well-regarded right now, specifically because they increase unsprung weight (the part of the car more closely coupled to the road surface than the passenger) and this impacts handling substantially. So instead we backport a bunch of the mechanical infrastructure that transfers power from a traditional ICE engine to the four wheels. We're paying that bill already, on almost all production EVs. Quadruple the power density and simple, 1-moving-part wheel hub motors look like a lot better case versus central driveshafts and mechanical linkages.

    • > Direct-drive, wheel-hub motors are not well-regarded right now, specifically because they increase unsprung weight

      It will always be lighter to not have the motor in the wheel.

      > So instead we backport a bunch of the mechanical infrastructure that transfers power from a traditional ICE engine to the four wheels.

      No, we do it because it's smart and efficient for freeway-capable vehicles.

      Wheels get banged up in use. They're easy to replace for different applications. They're exposed to 200 kph salt spray at hundreds of RPM. They are not a great place for motors.

  • > According to YASA, this is achieved without using exotic or expensive materials, so the design could actually be scalable once the demand kicks in.

    That is ever more special

  • I'd expect more applications in either aviation or mobile / portable power devices.

    As others have noted, battery remains a major factor in overall mass, and motor placement (in-wheel vs. driveshaft) is a concern in ground-transport.

    In aviation, battery limits overall range, but a high-power, low-range, lower-mass vehicle could be useful for short-hop flights, manned or unmanned, especially where payload considerations are paramount.

    Mobile-power applications (tools, transportable equipment) might also benefit from high power-to-weight, especially if this means that overall weight limits could be more readily met (e.g., total vehicle weight, total carried weight), or additional equipment (or battery) could be provided.

  • Better for robotics as well.

    • This may or may not be generally true. The needs around motors in a robot are more about control than raw output (some output is certainly needed). It is possible that this advancement in manufacturing will benefit there, but it is not assured by the information at hand.

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  • Batteries are the bottleneck.

    Even if motors were literally weightless and mass-less, EVs would weigh more than ICE cars.

    It's like making a more efficient CPU for your phone when all the power is eaten up by the cell-modem, screen and RAM. People wonder where the practical battery life gains are and theyre miniscule in practice

  • Only the absolute weight of a motor counts, because consumers of passenger vehicles do not require 1000 hp.

    How far does YASA's tech allow the motor weight to scale down, for applications where you don't need the power?

    Can you make it 2.8 pounds instead of 28, if all you need is 100 hp? Likely not.

  • The other aspect is that a smaller motor with the same power generally has higher efficiency, by necessity, since it has less heat dissipation. So higher power and higher efficiency and lower size/weight all go together. It’s a great synergy.

  • >In 2025, after a £12m investment, YASA opened the UK's first axial-flux super factory, in Oxfordshire.

    In Bay Area that is small investment in a startup which would be able to lease a small office

    >Could lead to significant efficiency gains for EV's, because 1/4 of the motor weight means better power-to-weight ratio...

    that would help VTOL a lot. Unfortunately YASA motors are priced for supercars and availability seems to be low. Until some factory in China starts making similar ones, there are not much chances on getting hands on such a motors.

  • OK, you can stop being so enthusiastic. We won't afford to buy any vehicles with these motors until the patents expire. I mean, I'm still waiting for epaper screens...

  • I don't see the weight reduction being very significant.

    If we take a Tesla model 3, I believe it weighs 1611kg, and the motor shows up at 80kg if you google it (no idea if this is correct). This YASA motor by comparison weighs 14kg. So, this would drop the vehicle weight by 66kg out of 1611, so that's a 4% saving.

    • I assume that means it would be more like an 8% savings on the dual motor variants? At what point does it become significant?

    • This motor is well more than twice as powerful as the Model 3 motor, so it could eliminate the entire weight of the second motor in the higher performance models. That’s 146kg, the weight of two adults, an 11% reduction.

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  • > because 1/4 of the motor weight means better power-to-weight ratio...

    1/4 of something that is a small fraction of the total weight of a car means very little improvement in overall power to weight ratio.

    I suspect that gaining 40% of car seat weight would be much more beneficial even if way less sexy.

  • saving 30 kg of weight on a 2000 - 2500 kg car won't lead to "significant efficiency gains"

    • The Ferrari 296 GTB weighs about 1500kg and the sports version 1300kg. For the cars YASA produces motors for it's much easier to increase the power to weight ratio by reducing weight than increasing power. I imagine an important design point for all of its components is to reduce weight.

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    • Weight reductions on an electric car are self-reinforcing. If you reduce the weight of a component, the battery can become (slightly) smaller, which again reduces weight. At a certain amount of reduction this will allow you to make the whole structure lighter, which will again allow for a smaller battery.

      So yeah, weight reduction on EVs is great.

      5 replies →

    • I agree insofar as the motor is not a Big Ticket Item, opposed to ICE cars where the engine block is going to be 10% or more.

      Tesla (I know) claimed a 30kg (?) weight loss on their Cybertruck (I know) just from moving their 12V systems to 48V, allowing for lighter cables at lower currents. Not all such potential is untapped, and my hunch is that there is more to be had with structural battery integration, battery cooling, and high voltage wiring.

    • Depends on your definition if significance, but I think they do. Every kg of useless weight you do carry, lowers your range. But sure, on its own it is not a magic game changer for heavy electric cars.

      For light weight vehicles on the other hand, it might be.

    • If you put several small motors on each wheel you might get some extra weight gains in the form of less transmission needed. Cables weight less than metal structural bars. But yes you are not going to be 500kg lighter.

  • There is no statement about the efficiency of the motor itself. If the energy conversion efficiency is low, then the weight savings will not matter and the car will have even less range.

  • > This is awesome. Lighter motors also make electric flight more viable

    The next innovation we need is Aerial refueling[1] for electric planes. High density swappable batteries and high altitude wind/solar plants that can swap batteries mid air. Perhaps some billionaire will develop a large fleet of these to service all flights! If no western billionaires, we just have to wait for China to develop this tech.

    [1]https://en.wikipedia.org/wiki/Aerial_refueling

    • A sufficiently compact electric motor enables mounting it in the nose-wheel of commercial aircraft, allowing it to be driven around like a golf cart. This means the plane can taxi without the use of its engines, just the power from the APU. [1]

      Also planes would not have to wait for a tug to pull back from the gate, which improves turnaround times for the airline.

      [1] https://www.wheeltug.com/

      1 reply →

    • Apologies for the turbulence, we're just flying through a thunderstorm to top up the batteries

    • Or laser power beaming from a satellite, or a ground station.

      Not very feasible, but an option that has been thought through.

      I guess there’s a system that’s gated to track dependent technologies, to track improvements and what they’ll enable.

    • Surely it would be easier to recharge rather than swap batteries? I wonder if in the future war will be like a turn based strategy game as everyone wait for drones to recharge before making a move.

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  • It will probably lead to cars that fail sooner and are cheaper to build

    • Okay cool downvote me but it's true, most of the weight is batteries and asking a smaller device to do more work will create more heat and wear components faster. It's not a new phenomenon.

A link to the press release https://yasa.com/news/yasa-smashes-own-unofficial-power-dens...

  • > 59kW/kg

    At this point why don't we get rid of the k prefix and write 59W/g?

    Edit:

    I was half joking, but various answers mention kW being standard for motors, kg being the SI unit for mass etc. All true, but as used here in a combined unit, which means "power density" it still would make sense IMO. It's not like the "59" tells you that it's a strong motor and hence you want kW to compare it to other motors. You can't, it's just a ratio (power to weigth). W/g just reads much nicer in my head. Or we could come up with a name, like for other units. Let's call it "fainpul" (short fp) for example :)

    59 fp is a new record for electric motors!

    • Because kg is the fundamental unit of mass and kW is typically used for electric motors.

      Same reason you wouldn't use m²/s³ even though that's also technically correct.

      4 replies →

    • Amusingly, given the other thread in here with people sniping each other over the metric system, I'm obliged to point out that kg, not g, is the fundamental unit of mass in SI, because even metric can't get away without some silliness.

  • A much better link .. and probably not to late to change it via [edit] on submission in your view..

    The YASA link is primary, links to test data and back story, and has more detail substance and authority.

This discussion is all about vehicles with large batteries, but how about hybrids? With light enough and efficient enough motors, all kinds of designs might become practical:

- Toyota-style hybrid drives could be a lot lighter, and they don’t need large batteries.

- e-bikes with tiny batteries?

- Hybrid aircraft? What if there was a battery large enough for takeoff and landing, a small motor (or pair for redundancy) for cruising and to recharge the battery, and motors and fans or propellers wherever is best from an aerodynamic perspective.

- Power tools.

  • The size of this motor is moderately interesting, but the power density doesn't really matter for most of the things you just mentioned. Almost every one of them is limited by the amount of batteries you can put in for both weight and power output reasons.

    • What do you mean? Modern LFP cells have quite high power density. LTO is even higher.

      An e-bike with a 100Wh battery and a 300W motor would be extremely useful if it were light enough: you could carry it up stairs, onto trains, etc easily, and it would give plenty of boost to navigate traffic for short distances and make it easier to go up hills. The idea would be that most of the energy would come from the rider. 100Wh of modern LFP cells doesn't weight very much, but you still need to carry around the motor and the structure to support the motor.

      In an airplane, you need a lot of power to take off, and weight is a big deal.

      8 replies →

  • My first thought too.

    While I see Toyota-style hybrids as designed for efficiency, there's also the performance hybrids like the new Porsche 911 T-hybrid where an electric motor spins up the turbocharger to eliminate lag while another integrated into the gearbox adds power. There is no "EV mode" so it doesn't need a large battery.

    Arguably the most important characteristic of a sports car is light weight, so lighter motors would be immediately useful there.

  • > Toyota-style hybrid drives could be a lot lighter

    The hybrid electric motor in a Toyota is already pretty comparable in weight to the motor in TFA, but obviously much less powerful. You can see the main hybrid motor of a RAV4 at [0]. If memory serves both the Camry and RAV4 hybrid models are only 2-300 lbs heavier than their gas counterparts.

    0: https://youtu.be/O61WihMRdjM?t=120

  • There's indeed a huge number of applications where lower weight electric motors could be useful.

The new YASA axial flux motor weighs just 28 pounds, or about the same as a small dog.

But how many footballs a small dog weighs?

The questions I have mostly centre around how much precision of power delivery it has - it is an all or nothing proposition, can it deliver 0.1% smoothly for real world use, and what is the MTBF / duty cycle / failure mode? I would imagine the last thing anyone would want is a locked wheel, or only one wheel delivering that much power. I know this is unlikely, but as someone with a 22-year-old ICE vehicle I do tend to take the long view on these things and want to know how they will fail as much as how they work. Same applies to the Tesla motors - is there much information on failure modes publicly available?

Ok so whats the catch with the technology? Its more powerful, smaller, all readily available materials. Some kind of strange shape, longevity challenge? Difficult to make so costs are tough to bring down?

Just noticed that they are owned by mercedes benz- they will kill it accidentally. Corporate wont be able to roll it out. They will try and capture all the value and kill its potential

  • Axial flux motors are difficult and expensive to make.

    Motors need to be made of laminated steel sheets to reduce parasitic eddy currents. The laminations need to be thin in the direction of the direction of the flux. For radial flux motors you just punch out a shape and stack a bunch of sheets up. For axial flux you have to wind a strip: https://15658757.s21i.faiusr.com/2/ABUIABACGAAgmviFqAYozvPw-...

    Each layer of that strip has a different cut in it, so its much more complicated to make. The shape and manufacturing method typically impacts efficiency; YASA avoids that by spending more money. Efficiency is an unavoidable requirement of high power density- heat is the limiting factor, and going from 98% to 96% efficient means double the heat.

    The mechanical demands on the motor are also much higher- radial flux is balanced since the magnetic force pulls the rotor from opposite sides. Axial flux motors are usually one-sided, so the magnets are trying to pull the rotor and stator together with incredible force. That also makes vibrations worse. Extremely strong, expensive bearings are required to handle it. With permanent magnet rotors you need a jig to lower the rotor into place; they can't be assembled by hand. That also makes maintenance more difficult and expensive.

    • >> Each layer of that strip has a different cut in it, so its much more complicated to make.

      You can roll a spool of that material and then machine the shape out of it. I've seen this done for axial flux motors. There are other approaches as well, and the cost differences get even smaller if you throw automation at the production process. I used to believe axial flux motors were one of those oddities that won't win in the end, but now that I work with them I'm not so sure. They are at least competitive with radial flux machines.

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    • Isn't the whole premise of this breakthrough that they don't need the lamination, and thus can stamp it out?

I'm curious as to the efficiency of the motor (basically, how much of the input electric power is converted to motive power).

If it isn't very good, then it might be excellent for drag races, but maybe not so many others.

Also, any power that doesn't turn into torque, is likely to be expressed as heat.

  • It would almost have to be very efficient -- they're saying it can do something like 500HP continuous, and it doesn't have enormous fins all over it for cooling.

  • Exactly my thought as well. You can have all the horsepower you want but if it doesn't convert the electricity efficiently, it's not going to be useful for normal consumer cars.

It's cool, but I think deploying motors without rare earth materials will be more impactful. The Nissan Ariya was ill-fated for other reasons, but it had a EESM motor that is easier to cool, more efficient at speed, and cheaper. That's where motor tech is headed. Power density just isn't terribly important in current applications, at least not past current sota.

It's easy to forget that most of the weight in an electric car is the battery. It's ICE cars where a lot of the weight is in the motor.

That being said, could this be adapted so that a 2.8lb motor produces 100 hp? That would allow putting a small motor in each wheel, thus completely eliminating axels, driveshafts, and allow recapturing the space they used to occupy. It also wouldn't significantly impact unsprung weight.

  • First, no, it won't scale like that.

    Second, don't forget that you're trading one complexity for another. Eliminate a drive shaft and you still have to get power to the wheel somehow, which means now you're running high power electrical cable in a very dynamic environment with exposure to the elements. On top of that, you need to cool the electric motor, so you're probably running some kind of fluid out to it. Not that it isn't a solvable problem, but it probably doesn't reduce the weight much, if at all, when the system is all added up. You'll find that while you eliminate an axle, you still need to mechanically connect the two wheels together (look at the rear subframe on an FWD car) for strength, which also reduces the weight loss. Then the steering on the front... etc.

    Until a more significant change than this motor (where maybe a 2.8lb motor could produce 100hp without needing active cooling), we're better off with "inboard" motors still.

  • Is it really easy to forget?

    • People used to say they would only get a Tesla if it was offered with a manual transmission.

      It's easy to laugh at, but there are still many people who haven't shifted, in their mind, to the differences.

      Even after driving EVs for over a decade, I still need to shift. My habit is to turn the car off and close the garage inside the car. My new EV only controls the garage if it's on, so I had to get used to closing the garage with the car on. There's still a part of my brain that screams "but carbon monoxide" every time I do it.

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Outperformance metric is basically power density. The model described is some 13 kg and delivers 750 kW peak, 350+ kW sustained.

(That's 28 pounds, 1000 hp peak, 470+ hp sustained.)

The 40% improvement is actually 36% and is versus the previous model of the same company.

  • Peak power is a number that can be manipulated. You just dump short circuit current into a winding. Even if that peak lasts for 1 microsecond, you can "claim" eye-watering horsepower numbers.

    I wonder if we defined peak as sustained peak over 100 milliseconds, or some more meaningful number, what that would do to the claims. You aren't really generating meaningful torque over 1 microsecond.

  • I sort of wonder how well these things can be scaled down.

    Wheel hub motors are obviously bad, for harshness reasons, but if you could have a motor like this weighing 1-2 kg, and put one on each wheel, that'd be okay.

    Power-wise this would be okay if things are linear. 26 kW per wheel sustained power output is more than enough for a light car. The question is what torque a scaled-down machine can be expected to have.

    • I'm wondering if it would make sense to integrate the rim, motor and wheel bearing into a single assembly to save weight and cost. That combined with the weight and packaging benefits of not having half shafts and differentials might make it worth it. Plus there can be additional benefits, like the extra maneuverability that ZF Easy Turn and Hyundai's e-Corner have demonstrated.

      30kW sustained/60 kW per wheel peak power is easily enough even for large passenger vehicles. Sustained could take 3 ton vehicle up a 10% grade at 120 km/h.

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  • Thanks. Do you also happen to know the power density of the motors in the average EV car? Because the article uses "nr of Tesla Model 3" as a unit, which is meaningless without further details about it power density.

    • The power density doesn't really matter unless you want to put the motor in the wheel. You need to keep the unsprung mass low.

      Basically all EVs have small and light motors compared to ICEs or compared to the battery. Shaving off ten pounds there is irrelevant.

      1 reply →

EV motors are not that heavy. Ok it is 1/4 of a tesla motor but would that make much of a difference compared to the rest of the car since the weight of an EV motor is in single % of the entire weight.

Sounds like it could be more important for drones?

  • It is important if you want to put the motor in the wheelhub. Too much unsprung mass kills vehicle dynamics.

  • Saving up even few % of weight while not compromising on comfort/safety is a holy grail for any decent car manufacturer.

    Not sure why the negatives in this thread (maybe too many folks hold TSLA stock?), this is properly awesome (r)evolution.

    • I do not know why people still think Tesla is a unique company. They are a regular car company now. Nothing more, nothing less. Yes, they disrupted the market and the reward is a standalone, viable car company. That is a huge achievement. But their disruption and uniqueness is gone. The rest of the car industry woke up and all are producing many more EV variants and EV cars in total.

It is great that Mercedes-Benz now owns a highly performant electric engine. But is this just an impressive lab breakthrough, or can it work in the real world for their cars? Which means enduring from freezing to high temps, hours of sustained driving, and years of that (or equivalent endurance testing).

  • It's not a lab model (according to the article), but it's likely aimed at performance cars. For consumer cars, 150 KW / 200 HP is enough and efficiency is more important than weight.

    Of course, when consumer car efficiency increases, they won't necessarily get higher ranges because the manufacturers will instead try to downsize the battery.

  • They've used their previous motors in production Ferraris and koensiggs and also in aircraft. They have the capability to make 100,000 motors a year so this is definitely not just lab stuff!

You could almost replace the disc brakes with these and have hub motors for free (in terms of unsprung weight). Depends on the torque and safety margin on the 700KW level of performance. For emergency safety you could have a mechanical short to let the motors dump energy into a big heating element as a last resort (risking wheel lockup) but this would truly be drive-by-wire braking.

  • > For emergency safety you could have a mechanical short to let the motors dump energy into a big heating element as a last resort

    That would be craaaazyyyy!! I'm imagining drag cars literally blowing liquid metal out the back when they brake hard..

> According to YASA, this is achieved without using exotic or expensive materials, so the design could actually be scalable once the demand kicks in.

So, no rare-earth magnets? And it will be cheaper than existing motors?

It's very hard to find any supplier who will sell an axial flux motor to the public.

I see lots of press from Yasa & Donut motors, but afaik no public pricing & relationships with select partners only.

Axial flux motors are so next level. Very little power needed per rpm. I’ve built a few tiny ones for FPV and they are a joy to work with. I’ll die a happy man if I never have to coil again.

> YASA, which is a wholly owned subsidiary of Mercedes-Benz, already produces motors that power some of the world’s fastest and most expensive cars.

Never underestimate the swabians.

First motor I saw in this category was much larger because it had massive mount points to attach it to the car so the torque would go to the wheels and not to destroying the motor.

This one has a narrow ring meant for 3/8” bolts? I guess if you’re buying a 1000 hp motor you can afford titanium carriage bolts.

  • I suspect this may end up in Mercedes Formula 1 power units, so that may not be off-base. Use whatever ridiculous materials you can to keep the weight and size down.

  • titanium has a low tensile strength compared to steel. I wouldnt recommend it even on a bike handlebar

    • Oh but they do. People have been making titanium replacement bolt kits for bicycles since at least 1993.

      Doesn’t change the fact that those are tiny bolt holes for holding a 750 kw motor. How are they affixing it to a vehicle?

28 pounds - that's gigantic compared to this https://now.tufts.edu/2011/09/05/worlds-smallest-electric-mo...

  • > "There has been significant progress in the construction of molecular motors powered by light and by chemical reactions, but this is the first time that electrically-driven molecular motors have been demonstrated, despite a few theoretical proposals," says Sykes. "We have been able to show that you can provide electricity to a single molecule and get it to do something that is not just random."

    "something that is not just random" ==> Probably a long way away from something in production. I wouldn't hold off on any urgent transportation needs waiting on this tech.

If used in power generation, would they open new options?

e.g. high RPM, or high torque options over existing generators?

So-called lighter or smaller electric motors with today's technology limited by a "passive-rotor" is the result of legacy packaging geometry, which will have the same result if equally applied to contestants. Only SYNCHRO-SYM has an active-rotor in the same package geometry that eliminates the geopolitical harm of rare-earth magnets but delivers 2x the performance in the same legacy package geometry.

Why do we even need to drive cars, why dont we all just have trailers and then an automated robot could pull it around. Decouple the drive train from the cabin.

  • With all the extra coupling hardware and surface area required, the reason is performance and weight. Modern cars are all about material minimization. It's easier to add a bump to the cabin and put a motor in that volume than it is to make another mini car.

    I think it would only make financial sense if it were like swappable batteries: you rent it all.

I wonder if this tech is already being used in F1, or if it makes sense to do so. The weight savings alone could easily make a championship winner.

  • There have been rumors for quite some time that Mercedes has the best power unit for the upcoming 2026 regulation set. It's entirely possible that this is part of that picture.

    "Sustained power output between 350 and 400 kilowatts" is also a bit interesting since that is basically right in line with what people expect out of the 2026 electrical component of the power unit.

Cars are probably fine without that engine. But for drones and robot actuators it should be a huge boon.

Great! When can I order one packaged in the form of a drop-in limited-slip NA MX5 differential?

How much torque can it generate?

  • Their website claims "4 X more torque and double the power densities of current technologies".

    A bit handwavy, but given the inherent torque advantage of electric, I doubt torque is an issue. If anything, a lot of EVs would probably do better with a touch less torque.

    Source: https://yasa.com/technology/

Tesla should buy Mercedes, they'd make a good team together.

  • Surely there is still some merit in having competition in the market place?

  • Mercedes should buy Tesla you mean.

    • One of my fundamental criticisms of Elon musk performance as a CEO. The vast stock market price and valuation should enable these sorts of transactions.

      It would enable Tesla to diversify operations move into applying its technology on a mass-market basis to hybrids without "damaging" the "purity" of the Tesla brand.

      It would enable more marques to target specific economic bands, international markets, etc.

      But no we basically have a car company that makes two cars.

      2 replies →

Yet Another Sale Abroad. Not a criticism of the YASA team. It’s hard to scale a company in the UK and foreign investment is a good thing in general. But still frustrating that the UK was unable to offer the kind of investment that Mercedes could to keep a company British.

  • We're a country who even sold our water to the highest international bidder ...

    What would make you think we wouldn't sell our tech crown jewels also? (throwing in our grandparents and children to sweeten the deal).

Everything but the Metric System: “The new YASA axial flux motor weighs just 28 pounds, or about the same as a small dog.” :)

  • I wonder if Americans don't have a mental image for measurement units so that they alway use some physical object as a reference. Sure, its useful to use a common object as a reference but I don't see that much often in other places.

    Most people usually understand what it means something to be 20 meters, 5kg or 2 liters intuitively. Like, when I hear that something is 60m tall I intuitively think if it as 20 story apartment building and don't benefit from the extra info about how this is like 18 elephants stacked on each other.

    • Yes I'm always a bit dumbfounded by this behavior as well. They always use weird stuff and I never have the intuition of the actual size, especially since the definition can vary depending on context.

      In this case, what is actually considered to be a small dog? To me it would be something that is close to the size of a cat but since it's about 13kg, it can't be that small, so that's more like a medium dog (I'm not certain, but I have a feeling that if you lay out things statistically this is what you would end up with). On the other hand, 13kg is very easy to get, that's just 13 liters of water, and it's quite easy to make a mental image for both volume and weight "feeling" that way.

      American units feel so impressive and random, it is the reason they always add those weird comparisons but often they make it even worse.

    • Which is strange, since one of their measurement units is literally based on a body part.

    • Americans do not do metric. Americans can’t even balance a checkbook. Hence the small dog reference for mental “clarity”. We’re dumb. Just look at the news…

      21 replies →

  • The link you're quoting, the one posted, is a second hand US report.

    The primary company link is from a UK subsidiary of Mercedes-Benz and is (almost) fully metric (the fundemental units US weights are officially defined with respect to (for more than a century now)).

    See: https://yasa.com/news/yasa-smashes-own-unofficial-power-dens...

      Earlier in the summer YASA achieved 550kW (738bhp) from a 13.1kg version of its new axial flux prototype motor, equating to an unofficial power density world record of 42kW/kg
    
      Now latest testing of an even lighter 12.7kg version on a more powerful dynamometer has shattered this record, with a staggering 750kW (>1000bhp) short-term peak rating, resulting in a new unofficial power density record of 59kW/kg
    

    Just those pesky trad bhp units left hanging like a chad in a Florida election . . .

    • > The link you're quoting, the one posted, is a second hand US report.

      You can tell, because a proper Brit would have given it as 2 stone, not 28 pound.

      4 replies →

  • If I were a self-respecting journalist, I would've used 3.26 gallon milk jugs. Small dog automatically goes to which breed? Chihuahua (fits in a toddlers purse) or Border Collie or Golden Retriever or Saint Bernard (needs an SUV/minivan)? 4 different classifications based on size!

  • Is even a 13 kg dog "small"? It certainly does not feel small if you are carrying it upstairs.

    • While there’s no formal definition, I think it isn’t. It would be considered medium sized. I live with a 4 lb dog.

      I’d say 25-50 lbs would be medium, small below that and large above.

  • Americans are very weird when it comes to metric. They often quote mobile phones as having something like "a six inch screen size but now only 12mm thick" - pick a measurement system people !

    • Canada is even weirder.

      After switching to the metric system ('70-80s) some things are still measures in imperial units. If you slice some ham at a counter in a grocery store, it's in grams. You then turn around and get a pound of apples and a gallon of milk. Nuts are in grams, and soda is in liters. Also the body weight tends to be in pounds. Tools are both metric and imperial. Speeds and distances though, thank god, are metric.

      All this is just kinda there and everyone's OK with it, but it is an epic mess if you think about it.

    • I like having more choices for units. Sometimes the "correct" unit is extremely inconvient to deal with, either because the unit sizes are oddly out of proportion with the things being measured, or the things being measured have odd ratios with the units. Sometimes even making your own unit system or going with pure ratio relationships between objects is the most useful and effective way to measure things. And I feel that people who only ever use a single system of measurement often fail to see it and put themselves at a large disadvantage.

      To me using only a single system of measurement is the same as only ever using a single number base. Yeah it helps to have a standard number base everyone can use like base 10, but that doesn't mean we should try to eliminate other number bases from our vocabulary or understanding because they obviously have situational advantages.

      Also from my personal bias I much prefer fractional measurements and people go apeshit if you use fractional metric units but don't blink an eye at fractional imperial or other 'non-standard' measurements.

Axial flux motors are such an obvious and simple to build design that I don't understand why they aren't used more commercially. I've mainly seen do-it-yourself projects to build them for home windmills etc.

- divergence -

This is perhaps my greatest frustration with wealth inequality. Billionaires like Elon Musk (not to single him out of the thousand others) sometimes fund innovative projects initially, but seem to get lost in the weeds doubling down on evolutionary tech, while missing obvious opportunities in fringe tech and old ideas that were suppressed.

For example, the Tesla turbine could have been used for an onboard generator, and what better opportunity than to build a hybrid Tesla car using it? Its main drawback is that it gets fouled by combustion products (with secondary drawbacks in low torque, noise, etc). So why not use natural gas, propane or hydrogen? Why not use an external combustion system that heats air and runs it through the turbine in place of using a larger (due to low compression) Stirling engine? Why not mount the turbine in sound dampening material or a vacuum? These are all trivially overcome engineering challenges. Yet we can't buy a cost-effective mass-produced Tesla turbine or even a Stirling engine of any appreciable power online.

As we see more and more of these missed or suppressed innovations by moneyed interests, I can't help but come to the conclusion that wealth inequality is the largest force stopping widespread prosperity, especially the kind brought by automation to provide basic resources. We can claim that so much progress has been made possible by crony capitalism, for example the computers we are writing and reading this comment on, but I believe that they exist despite concentrated wealth, not because of it.

And I'm worried that access to fee-based AI will widen the wealth gap even further. Because people with money will be able to pay AI to do their jobs and get paid, while people without money may be forced to do those jobs by hand performatively under ever-increasing pressure as the cost of AI only decreases due to economies of scale and Moore's law. So that the main goal for moneyed interests could become to deny access to capital to the working class so that they can be exploited. Even though it would be far easier and more beneficial to more people to distribute the costs of some minimal level of AI to everyone in the world.

I dunno, the more I see these exciting innovations that could practically be built for cost of materials (28 pounds of copper costs less than $150 and is the most expensive component) yet never reach widespread adoption - while other inferior products that use more material flourish - it makes me question if our market-based economy even works anymore. I'm not saying that older (antiquated?) alternatives like socialism/communism would work better today, just that there may be a post-scarcity 21st century economy where patents that could increase equivalent personal wealth by orders of magnitude are put into the public domain. Not for money, but as automated and open source goods/services/resources having equivalent value to what money would have provided. The closest I can get is stuff like solarpunk, which still hasn't caught on for reasons I don't understand.

Edit: before I get flamed too badly for this comment, I should add that neodymium magnets could perhaps cost more than copper, and/or be a scarcer resource. If I were working on this type of motor, I would try to get similar performance from non-rare-earth magnets and aluminum wire, as well as explore hybrid motors that achieve say 80% of the power and efficiency using only 20% of the rare stuff. On that note, we are long overdue for mass-produced graphene and carbon nanotube wire. We need a definitive answer as to whether they are safe enough to use commercially, or if they are a dead end like asbestos. I don't understand why billionaires don't put more money into getting this sort of first-principles "real work" done. If I won the internet lottery, I would set up a foundation with an endowment to tackle these pressing problems and invite hackers through grants, sort of like what MacKenzie Scott is doing.

  • I regret writing this comment.

    It might not make sense to younger people, but for me growing up in the 1980s, there were many decades of tech stagnation where basically all alternatives to internal combustion engines were suppressed. And the people who made vast fortunes didn't care about disrupting the status quo, so we were forced to live with substandard tech and pay a premium for the privilege. It wasn't until Elon Musk disrupted the car industry with Tesla starting from 2004 that anything changed, which we take for granted now. I really idolized him before he lost his wunderkind status by falling for political propaganda like a mark. Maybe that's my own projection, I don't know anything anymore.

    Whereas today, tech is evolving so rapidly that we don't have time to invent much before the singularity hits in the 2040s. We're facing a different existential crisis now, one of finding meaning when so much happens through manifestation outside of our own actions, instead of facing the void that we can't contribute due to the realities of the time it takes to afford the cost of living (a theme from Fight Club). So my points are maybe anachronisms now, frustrations from an era that no longer exists.

    Why I got triggered by this motor: 1000 hp at 28 pounds is enough to lift a large car or truck. The rule for helicopters is about 5 pounds per hp (more with a longer prop that has a higher aspect ratio - edit: the Mars Ingenuity drone gets 3.6 lbs per hp in at atmosphere 1% as dense as ours). So 4 of these motors would make a quadcopter the likes of which we've never seen before. It's almost Star Wars tech IMHO. We're talking extremely high ceilings like 50,000 feet or more. Drones that fly at 400, 500 mph or more, even close to the speed of sound.

    And we could have had this tech a long time ago, because it's not especially complex. It's just that nobody devoted the small investment for the research. Same for lithium iron batteries, especially LiFePO4, which could have arrived in the 1980s or 1990s because they're so easy to make. Possibly even the 1960s: the SR-71 flew in ..1964! But we had other priorities.

    Anyway, it's a great accomplishment and I'm happy for them. I just mourn what might have been had the geopolitical situation been different.

> It can also sustain between 350 and 400 kilowatts (469–536 horsepower) continuously, meaning it’s not just built for short bursts, as it can deliver massive power all day long.

On what battery?

  • Pretty much any modern car battery out there. Many of those allow 350 kW charging, discharging that quickly is even easier.

  • I wanna know how they keep it cool, even if it's 95% efficient, that's 15,000 watts of power to dissipate.

Feels like a vanity metric, electric car companies don't boast about their cars having X horsepower. Not many people care about horsepower because either way there are speed limits on the road.

I think electric motors should focus on other vectors.

  • Car companies, both electric and non-electric, frequently advertise rated horsepower of their vehicles, even non-performance vehicles. In the US, horsepower is one of the key metrics for a vehicle overall.

  • People only stopped caring about horsepower recently because it became so cheap that everyone has more than they can utilize. HP use to be an important metric in a car because it was the main limiting factor in speed and capacity. Today engine power is rarely the top limiting factor, the tires, suspension, transmission, and driver ability are far more important, but far harder to quantify for marketting bulletpoints.

  • Every car listing, review and so on mentions either the bhp or kW, along with the 0-100km/h or 0-60mph which is functionally the same as listing the horsepower to weight ratio.

    • Yeah, but 0-60 doesn’t really matter much for EVs at this point. Even big suv/trucks are hitting supercar numbers from a few decades ago.

      Cornering / handling matters. So does tire wear, and how powerful the regenerative braking is / how many motors there are. (ABS and traction control via electric powertrains is much more responsive than via brake pads).

I am heavy motors guy, and this is my EV. She weighs one hundred fifty tons and drives four custom-tooled motors at one thousand horsepower per wheel.

It costs 10,000 Wh to power this car.. for 12 seconds.