If you're any kind of a car person, you owe it to yourself to check out the rest of The Autopian - it's an independent car site founded, owned, and operated by deeply weird car people, and it's absolutely amazing.
Scotty Kilmer from Houston enters the chat to talk about how new cars are plastic garbage and how their low profile tires look "cool" but are woefully fragile.
Crumple zones perform a very specific function in the sequence of airbag deployment (letting the sensors crash and bags deploy before the cabin starts decelerating). The speed window at which they will appreciably reduce the deceleration in the cabin is well below the speeds at which a seat-belted occupant of an airbag equipped vehicle has to worry about serious injury. Crumple zones are undeserving of the worship they get. If you want to worship something worship side curtain airbags. They save a lot more life and injury than crumple zones. Pre-tensioners are also another feature that I'd rather have than a crumple zone. As a general rule, features that directly keep the occupants from hitting things are far more beneficial to outcomes than stuff that acts upon the whole vehicle.
Secondly, it is perfectly possible to design cars that do not need tons of invasive repairs from minor fender benders. Revise bumper and front/rear cosmetic design to allow for effective bumpers (see also: the 1980s) and tune crumple zones to need higher forces to deform them so you don't have to potentially replace a whole car over a 10-15mph collision. The tradeoff here is that the speed range at which crumple zones do much would move up which is good for real world performance bad for scoring that perfect five stars in a low speed lab test that actually helps sell cars.
If you're going to make blanket assertions that safety tests are invalid and/or that the engineers designing cars don't know what they're doing, some references are probably called for.
> If you're going to make blanket assertions that safety tests are invalid and/or that the engineers designing cars don't know what they're doing, some references are probably called for.
Can you please cite where I stated, or hell, I'll settle for strongly implied, "the safety tests are invalid" or that "the engineers designing cars don't know what they're doing".
The person I am replying to made a trite low effort comment. I, without calling them out like they deserved, explained that the situation is more nuanced and their opinion is slightly off mark. You then replied with another trite low effort comment straw-manning me. FFS this is ridiculous.
OK, you said, "...which is good for real world performance bad for scoring that perfect five stars in a low speed lab test that actually helps sell cars." This strongly implies that you believe the lab tests are not valid for their purported purpose of making cars safe, but are rather more of a marketing gimmick.
You also said that designers should, "Revise bumper and front/rear cosmetic design to allow for effective bumpers (see also: the 1980s) and tune crumple zones to need higher forces to deform them so you don't have to potentially replace a whole car over a 10-15mph collision." This strongly implies that the bumpers as they are currently designed are crumpling needlessly at low speeds, and that they could be made to not do so, like the bumpers of the 1980s, without compromising safety, hence that the engineers designing them are not competent. Although admittedly in retrospect it could also be that the engineers are designing to the aforementioned tests. Regardless it's an extraordinary claim, requiring evidence.
Your first paragraph also makes a number of claims, many of which I'm sure are true. Certainly curtain air bags and seat belt pre-tensioners have been shown to save lives. I recall reading a study on the positive impacts of adding pre-tensioners to the back-seats of vehicles a while back. But again I don't see anything supporting the claim that crumple zones are ineffective, or specifically, that, "The speed window at which they will appreciably reduce the deceleration in the cabin is well below the speeds at which a seat-belted occupant of an airbag equipped vehicle has to worry about serious injury." That could be true, but it's not supported here.
bro but rotary engines, you need an RX7 or I hear GT3000s are fast and shit but your bank probably won't give you a loan for a used Mitsubishi. maybe your mom will let you hold on rent for a bit??
Just took a quick scan - funny, intelligent, in-depth technical content in here but very approachable. This has definitely hackernews community quality to it.
That was a great article that makes me very happy about how Ford are approaching EV utes, I've often noted the tendency to make EVs weirder than their ICE equivalents. Well done Ford.
Looking at photos of the F-150 Lightning chassis, it seems like a pickup truck's body-on-frame design has a nice unintended benefit of being easy to convert to electric. The "frame" doesn't look so different from the "skateboard" EV design that's common.
A lot of converted gas to EV cars like the Genesis Electrified GV80 rob interior space for shoehorned batteries, but the F-150 is all gains with that massive front trunk.
I had the opportunity to design my own set of wheels with a friend for my Mustang GT. I put a thread together with photos of the process from start to finish, it was a lot of fun. I don't have the Mustang anymore, but the wheels are stacked in my garage awaiting a future project. https://www.mustang6g.com/forums/threads/arcane-stellar-–-a-...
One day, I believe car design regulations will be amended to allow fully electric braking (ie. no hydraulics, drums, rotors, or pads). At that point, the motor can be moved into the wheel (unsprung mass = bad, but weight savings from not needing an axle or gearbox will outweigh this). Suspension and steering design is then far easier, because there is no axle to need to keep straight.
Braking redundancy will be achieved by having motors/brakes on all four wheels, and within each motor 3 independant phase coils with independant controllers, such that there are effectively 12 brakes on a car. Normally the controllers work together for smooth braking, traction control, software differential, etc. But even after 3+ failures braking performance should still be satisfactory for an emergency stop.
Obviously braking energy needs to go somewhere. In the happy case, it's regen'ed into a battery. If the battery can't accept it, it gets dumped into dump resistors. If the dump resistors fail, it gets dumped into motor coils (of which there are 12 remember). Obviously the motor coils will heat up very fast, so this is probably a one-use-only failsafe, like airbags.
So the whole system (except the pedal itself) is 12 way redundant.
So a big reason why this probably wouldn't fly is that it has a common mode failure which is loss of power. Most EVs don't use permanent magnetic motors so it needs power to be able to use the motors for regen. So lets say the relay fails from the main battery pack suddenly you have no power, and no way to energize the coils in the motors to use them to regen. This could be mitigated by using permanent magnet motors but you still have the issue if control power is lost the vehicle cannot stop. The beauty of hydraulic brakes is that they work really well with power, but still function without it.
Interestingly enough, I've had hydraulic brakes fail on me for two different cars (thankfully it was 20 years apart, but still I would have preferred that the first time was the last time).
iirc both times it was some sort of brake fluid leak.
So, while I totally agree that having motorized breaks is really scary, hydraulic brakes can fail as well.
I've also had two cars lose brake pressure. I'm very thankful that the cable-operated parking/emergency brake was functional on both cars; it saved one of them from going through the back wall of the garage.
The cable-operated E-brake definitely doesn't stop the car anywhere near as well as the power-assisted hydraulic brakes, but having two different braking methods can be a literal lifesaver when one system fails. (And all systems fail! I'd previously had two other cars where the E-brake didn't work.)
I've never had my breaks fail on me. I also don't use the parking break that often. I would be so proud of myself if I realized what was going on, remembered that the e break exists, and used it before hitting the back wall of my garage.
When the hydraulics failed (brake line exploded) on my old vehicle I discovered that the cable is also attached to the brake pedal, so I didn't have to play games with the parking brake mechanism. There is a world of difference in braking force though, it's like pushing on the side of a brick building to gently encourage the vehicle to stop. I was lucky that I was driving a manual so I could also downshift to kill the speed.
I had the engine fail (timing belt broke) and that also killed the hydraulics in that car, very different behaviour of the brakes compared to normal and you need a hell of a lot of pressure to stop but it still works. Downshifting was not an option since the engine didn't work anymore.
You are probably referring to the brake assist mechanism in all cars after the 90's. It uses vacuum pressure from the engine to help you push the pedal down. Without the engine running, the brakes will work ~3 times, and then they'll get super hard to press - but they will still function if you have leg muscles strong enough to work them.
I don't deny that there can be physical failures to the systems. And I also drive a hybrid currently that most of the time only uses the electric motor for slowing down, I don't find using the motor for braking scary. I personally see having both regen and hydraulic brakes on a vehicle a great step forward in redundancy and safety.
Electrical slowdown in hybrids does not provide redundancy for emergency braking. The battery has to absorb like 500kWt during 1s, this is well outside what a small battery can do.
Redundancy doesn't mean it will bring the car to a stop as quickly as hydraulic brakes, it is just another means to bring the car to a stop safely. From personal experience I could safely get my car to a stop in many situations without using the friction brakes at all.
I had _a_ brake caliper jam on my tundra. Completely frozen sliders on the caliper. The good news about hydraulic brakes is that the other circuits on the brakes still worked fine! I actually didn't realize the caliper was dead for (likely) a few months. With modern cars, each wheel is independent, so leaks and failures are more failsafe.
“It still kind of works without power” was an idea that kept hydraulic actuators in planes for a long time. But now most new planes are fly-by-wire (fully electric). Reliably stopping an electric car in an emergency should be a solvable problem.
So the fly by wire just means it is digital control to the hydraulic actuator instead of a physical cable running from the yoke or something to the actuator. They have not gotten rid of hydraulic actuators yet, they are working do that in the future but that is still a long ways out. Aircraft power systems also have significantly more redundancy so loss of control power is not a common mode failure due to have multiple dissimilar power sources.
The air brakes used on heavy vehicles (semi trucks, etc) have a very simple fail-safe. You need power to not brake. I.E. Air pressure is used to disengage the brakes. If you lose power/air pressure, the brakes engage and are stuck engaged.
That is easy to accommodate as you can design the electronics such that when there is no power they cause maximum braking force and dump energy into the braking resistors. This can be done completely with power taken from the motor itself and if it’s not turning to generate power, then I would expect the parking brake system to engage, eg: a spring defaults it to “On” and power is used to keep it disengaged.
This can only be done with permanent magnetic motors which is not the norm for EVs for many reasons. In a non permanent magnetic motor on loss of power there is no energy to dump into braking resistors since the motor is not causing any resistance because the coils have been de-energized.
Most EVs have permanent magnet motors of some flavor right now (some have both a PM motor and a pure induction). I would assume that if you were having the motor be the primary braking system, and it was induction, there would be a tiny cheap magnet installed in it to generate bootstrap power to prevent exactly this scenario.
An even simpler design is to assume that the car can only start moving when there is power. If there is a loss of power while moving, then you can use the energy in the HV capacitors in the inverters to make a bootstrap field. That can be maintained till the car stops (and the user still has control of when/how much to brake). When the car comes to a halt, the parking brake is applied, and it won't move again till repaired.
All of that can be done with software-only - no hardware changes needed.
So rather than coasting to the shoulder when you run out of gas your tires immediately slam full on coming to a screeching, uncontrolled stop in the middle of the highway?
hah. I didn't see this before I wrote my comment. Really makes you wonder about this common SWE fantasy of mew ways to turn cars into big electronic touch screen devices, whether the people dreaming these ideas up have ever actually driven a car.
Nope. If your car lost power for whatever reason, the system would scavenge power from the inertia of the car and the brakes would still operate as they do when the car is operating nominally. The 1-10w needed to run the braking system is a rounding error in comparison to the 4-10kW of wind/rolling resistance at freeway speeds.
That would be the default of this system if the brakes are still able to communicate with and provide power for the brake pedal. Basically if the brake system lost external power, it would get the power needed to run via scavenging it from the motors. Once the vehicle came to a stop, it would then loose power and the parking brake would then engage.
The slam on brakes case would only trigger if there was gross damage to the braking system, where you might have bigger things to worry about.
I think you've lost sight of the initial concern that was raised. There's still a common-mode failure of loss of control power.
Control power is different from actuation power, the latter of which is what you're addressing. And it's not "gross damage" because it's a common-mode failure, so you can't just ignore it like that.
To lose local regen braking derived power requires a failure of the cars systems similar in nature to one that would cause loss of hydraulic fluid or air in a traditional braking system.
It is trivial to derive control power from actuation power - at least enough for a few can-busses that run from each wheel to up-to-12 independent sensors on the brake pedal.
It's trivial if you're doing an opportunistic design, but it's challenging to match the safety and reliability of a hydraulic system while beating the cost.
>That is easy to accommodate as you can design the electronics such that when there is no power they cause maximum braking force and dump energy into the braking resistors
This is still uncontrollable failure. What if the car is in the third lane doing enough speed and there's some cars behind? I assume no ABS, because ABS can't work with locked up brakes. This means no steering, just skidding whatever way.
Having no power would be hard as the brake system can easily generate power to operate itself if the vehicle is moving (and if its not moving that is what the parking brake is for). This is more of a scenario that occurs when there is a catastrophic failure in the braking system, such as the motor control electronics getting damaged.
So fallback in the case of power loss is you don't come coasting to a stop, your car just suddenly and unexpectedly slams on the brakes? What's it do for recovery, accelerate into the car in front of you?
This is entirely dependent on how your vehicle is designed. Pulling the electronic parking brake in my car (Audi S4) at a decent speed applies maximum braking effort to all 4 wheels simultaneously. It'll practically pop your eyeballs out.
Define "decent." I lost all hydraulic brakes on my 87 Toyota pickup due to a hole in a brake line and I had to drive it to the repair shop using only the cable-operated handbrake. Granted, I didn't go on the interstate, but at some point I was still doing 35-40mph.
Hold up capacitors definitely could extend the length of time the brakes would work but it would depend on what the power failure was and how long you need to brake. A mechanical fail safe just seems like a worse version of hydraulic brakes.
Interesting. Is there no way to design the circuitry so that when given no input, it defaults to a fully brakes-engaged mode? I’ve only worked with PM motors, so I know how that sort of h-bridge could be designed, but my knowledge of non-PM motors is fuzzy at best.
Well, it is certainly a very shaky proposition, and the car will probably be a total loss.
But there are ways you could walk away from this.
You see some pretty crazy crash survivals in race driving, for example.
And I remember stories from a few years ago, when Ford had a recall on F150 tires because they tended to blow out at highway speeds, with an effect similar to full wheel lockup-- yes, people died, but others didn't.
So looking into it a bit there are what is called Eddy current brakes. In the section of disk eddy current brakes it talks about the power tool implementation where there is just a metal disk and the magnetics are pulled away from the disk when the device is powered on and passively return to the disk when power is removed. Something like that could work, but I am unsure of the size of magnets or disks necessary to adequately stop a vehicle. Most likely you could also add a normally closed relay hooking the motor to a resistor load. So when power is applied the resistor load is disconnected, and in a loss of power event the motor is directly tied to the resistor load.
Eddy currents develop in proportion to the speed of the moving magnetic field. So if you used eddy currents for braking, it would be most effective at high speed and gradually have no stopping power at low speed.
That is mostly true about regenerative braking as well. Once you hit a certain speed the vehicle has to use some energy to get the motors to actually stop the vehicle. Usually EVs and such will just rely on the friction brakes for the last bit but some cars like the Bolt will automatically use some energy to slow the car to a stop so you can use do one pedal driving.
I'd imagine this was introduce adverse failure modes like - slamming to a stop without warning within seconds on the highway if power is lost, rather than coasting to a halt... and then being untowwable as the car can't be put into neutral.
Tesla's that lose battery are already a challenge to tow as the parking brake cannot be disengaged without power.
Hmmm. So you're travelling along the interstate at night, you lose power and your car screeches to a stop in the middle of high-speed traffic and your lights are off.
I would love to be present at the DFMEA (Design Failure Modes Effects Analysis) meeting when this came up!
I actually don't think that's a bad idea... Specifically, most cars can only brake at about 1 G, and if that's insufficient, they use crumple zones and airbags which brake at far more than 1 G.
If emergency braking could use an explosive-spike-in-ground deceleration at say 5 G, then far more crashes would be survivable.
I think the reason it hasn't been done are human reasons - users don't like the idea that jabbing the brake pedal hard will mean they have to pay tens of thousands of dollars to repave the road and replace their spike.
So a fly by wire aircraft might not have physical cable moving surfaces, but most of them have a backup mode that relies basically entirely off of physical switches and direct communication with the surfaces. Those modes are only used in extreme emergencies but they are still designed into the system. Also what works in airplanes doesn't always translate to cars. Aircraft have rigorous maintenance requirements, while cars leave the manufacturer and might not have any sort of inspection or maintenance done for 20 years.
>, but don't you need a mechanical (non electrical) system for parking breaks?
To some of the replies... I think some clarification needed because the wording caused folks to think of something else such as electronically _controlled_ physical brake pads: https://en.wikipedia.org/wiki/Electronic_parking_brake
I think the gp was trying to ask about feasibility of electric _powered_ magnetic field resistance braking ... similar to an exercise bike ... which would require constant electrical power source. (Similar to : https://www.google.com/search?q=magnetic+resistant+braking+o...)
Magnetic field resistance brakes is practical for regenerative braking but not safe for parking brakes on an incline if the batteries run out of juice. The context is the gp's premise of no physical friction brake components via "(ie. no hydraulics, drums, rotors, or pads)."
You do, yes. But that can be a metal pin the size of your pinky finger. It's a super easy engineering challenge compared to the regular brakes that slow down the car, which, when emergency braking a 2 ton car from 100 mph, needs to briefly absorb nearly 1 megawatt. Thats the power used by 1000 houses, which is a lot to absorb in a lightweight system that needs to still work if part of the system fails.
You don't, many modern cars have electronic parking brakes with small electric motors mounted on the rear calipers which push the brake pads against the discs when activated.
I am very glad you commented here as my initial skepticism of your claim lead me to do a spot of research that answered several unresolved questions I'd had about one of the most obnoxious features I've ever seen in a new car. My mother in law has a car with (apparently) electronic parking brake and I have loathed everything about it from the moment I first sat down in the car. This at least explains why an utterly unintuitive double toggle button replaced the "standard" mechanical lever on the center console and what notional benefits (hill holding) come with this system. I'd hate this a lot less if the manufacturer had included a tell-tale of some kind to visually indicate if/when the ECM thinks the P-brake is engaged.
If it's using brake pads, then it's still a partially mechanical suggestion. The comment at the top of the thread was suggesting doing away with brake pads entirely!
I would think so too. Any parking brake has to be a fail-safe type brake which has to function in the absence of electricity. Hence, as you mentioned, purely mechanical.
Hub motors will be common on scooters and other small electric vehicles, but it will never make sense on full sized cars. The size of motor required to move a car with the acceleration and speed modern traffic demands just won't work in a hub. Reduction gearboxes and axle-shafts already represent a pretty tiny fraction of the total mass of drive units on EVs and there are no mass savings coming on motors that will somehow get them into the range of acceptable unsprung weight, even axial flux motors.
The whole industry is working on tighter integration of the drive unit components to reduce things like cooling circuits, length of high voltage cable runs, and the total mass of the components required to move the car. No one is working on splitting the motors out into the hubs.
As you point out, unsprung mass is bad. Especially for something like a motor it's beyond bad, it's a complete killer of ride quality and reliability. As sprung mass the entire drive system can be isolated from all the knocks and oscillations that happen from driving around. A hub motor will get crashed and bashed around and have a miserable MTBF. The occupants will hate the car since it will have awful handling and hitting even moderate-sized bumps will be terribly unpleasant. Lighter stuff like scooters can get away with hub motors since there just isn't that much mass to begin with, but cars are huge now.
Aptera is planning to use hub motors, but their car is the vapourist of wares and relies on being counted as a motorcycle under regulations. Their basic engineering just doesn't work when scaled to a 3500 pound car and beyond.
This is interesting because it also potentially solves the problem of particulate pollution from brake dust. There’d still be pollution from tire wear so it’s not a perfect fix but it gets partway there!
I could not find anything that would prevent this in my brief skim of FVMSS 105 (US car brake regulations). The regulations are mainly about the performance of the braking system (eg: needs to stop car 10x from 60mph in under a specific distance) and only care a little about the specific technique.
You should see what you propose on cheap cars if motor pricing becomes less than the cost of regular hydraulic brakes.
> S5.1 Service brake systems. Each vehicle must be equipped with a service brake system acting on all wheels.
What is a "service brake"? Notice that the regulation you linked to includes requirements for EVs that have braking regeneration as a component of their "service brake".
It turns out that the top-level of FVMSS [1] says that "service brake means the primary mechanism designed to stop a motor vehicle."
So I think you are exactly right. There is nothing in the law that says you can't use a 100% brake regen system in an EV. It just has to work and meet the performance standards (and perform regen on all wheels). But I'd guess that you aren't going to see the traditional brake system disappear unless it starts getting in the way. They don't cost a lot (relative to the price of the car), don't weigh a lot, are really reliable, and work really well.
> Suspension and steering design is then far easier, because there is no axle to need to keep straight.
I don't understand what you mean by this. Isn't independent suspension already a thing? Each wheel has independent up/down movement because there is no axle that remains straight (driveshafts are independent from each other in both FWD and RWD).
There are no up-down movements in full size cars and trucks, some kids toys maybe. Everything bigger moves an arm along a radius, which is "close" to up and down but not up and down.
Tire friction usually works on a vector-like system so being able to move more up-down rather than along a radius means maybe you'd get a couple percent more friction forward and back if not moving a little side to side when moving up and down. Which sounds useless, but 5% more usable tire friction means an improvement in braking and cornering performance which either makes the car safer or could theoretically make it cheaper/lighter to compensate.
You should take into account that regen braking (even with resistors) only works at high rpm. The final phase of the braking you need to put even more energy into the coils on top of what the they already must dissipate for braking the car. Electrically, you would need to run the engine in reverse to come to a full stop.
> You should take into account that regen braking (even with resistors) only works at high rpm.
It's note even with resistors it's only with resistive braking that this applies.
If this is an electric car then the inverter can be programmed to give pretty much any braking force you desire just by altering the phase of the driving waveform. This can be done at any rotational speed.
My Model S can dump 50 kW back into the battery so long as the battery is not fully charged. At 60 km/h the kinetic energy of the car is about 300kJ so the car can be brought to a stop in about six seconds purely by regenerative braking.
In the final phase of braking the car has hardly any kinetic energy left so the huge 250 kW motors can easily bring the car to a halt and hold the car still just by balancing the magnetic forces in the motor against the motion of the car or gravity. In fact this is exactly what it does when running on traffic aware cruise control in stop go traffic, whether on level ground or on steep slopes.
I'm looking forward to the day where beamed power (e.g., MASER) will allow us to ditch most of the batteries too, with a tow trailer battery pack for trips into the deep country. It makes no sense to me to accelerate and decelerate over a ton of battery pack and have to deal with so much regeneration loss when we could just have overhead beamers optically track vehicles and cut power whenever a stray bird enters the picture.
It probably makes more sense then a huge infrastructure build of giant maser units that would have to be able to simultaneously track hundreds of vehicles on every dense street corner and then you would have to put up mitigation for all the reflective power losses going through windows into peoples houses.
With no axle it'd also be a lot easier to allow them to turn 90 degrees (or 360(+), I'm just not sure there's any point), and have all-wheel turning, for optimal (and stupidly easy) parallel parking.
I used to make Lego vehicles like that (well before I could drive), because it felt so silly as a passenger being parallel parked I suppose.
Not a mechanical engineer. This design is interesting. Do you think regulation is the only reason this did not happen yet? Why is nobody building this otherwise?
* Regulation. Plenty of countries are very specific about the exact mechanicals of brakes, in laws that are 100+ years old from when runaway cars killed people.
* Unsprung mass. Cars handle better if the wheels are very light and all heavy bits are in the body of the car.
* Large diameter motors are harder to design - there is no opportunity for a gearbox, so you lose one design parameter, and need the motor magnetics to be right around the rim of the wheel to make up for it.
* Difficulty of making the air gap within the motor very thin at such large diameters - you end up needing super large diameter roller bearings.
However, I think despite those downsides, the benefits outweigh them.
1. Braking generates a LOT of energy which needs to be sent somewhere very quickly. Each wheel might need to dissipate hundreds of kW of power, simultaneously, on-demand, at any time in normal situations where mechanical brakes function fine today. This is not inexpensive.
2. Today, most EVs do not have 1 motor per wheel, which would be almost surely required to implement this type of system effectively. That's also not inexpensive and unless you can actually put the motor in the wheel-area you still need an axle to connect the motor to the wheel due to the suspension and steering movement, and then that axle would need to be able to sustain these braking forces.
It surely could be done from an engineering point of view today, it's just going to add tremendous cost over using conventional mechanical brakes regardless of if those brakes are a traditional hydraulic type or if they're a brake by wire system.
I suspect vibration, and the need for 4 motors instead of 1. I'll bet it'll be a long time before motors are cheaper than brakes. Also, braking involves a lot more torque than accelerating or cruising.
I think having one motor per wheel is very useful in terms of all-wheel drive (and braking) -- being able to selectively apply varied amounts of power to each wheel depending on conditions.
Not sure I'm convinced by the torque claim -- we've seen cars skidding / losing traction in both scenarios (accelerating and braking). ABS brakes were developed specifically to prevent that (and so was Traction Control).
My experience with electric vehicles is limited to a Boosted longboard, so take this with a grain of sand -- but it seems to me that electric motors are as effective at braking as they are at accelerating.
I'm thinking in terms of f=ma, or the equivalent in terms of torque. I can live with my car getting up to highway speed within a much longer time duration than how quickly it needs to slow down if I hit the brakes. So the brakes need to exert more torque on the wheels than the motor does.
Putting a motor on each wheel could have some performance benefits, but I'm not sure I'd pay for it if I could get a single-motor car for cheaper. I'm talking about "econo box" performance, which is all I want anyway.
Modern brake systems are so good though, they're cheap, powerful, reliable, and easy to service. I am not sure that the juice would be worth the squeeze
Gearbox serves more purpose than just getting the power to the wheel, it also improves the efficiency of the motor and\or expands and optimizes the usable speed range of the motor.
Also cars can stop way harder than any regen can, massive amounts of energy will be at play and likely any solution is more complex than just grabbing a rotor, which is a more direct way to heat dump
Observe that the kingpin axis is entirely inboard of the tire, almost vertical, and the scrub radius is such that the axis meets the ground inboard of the contact patch of the tire (in other words, it doesn't really "scrub" the tire when turning).
What stops the suspension from actually steering is the steering system itself and the hands of the driver holding the wheel. You can visualize that in the picture above or below; if the ground pushes the tire rearwards at the contact patch, which is a few millimeters outboard of where the kingpin axis intersects with the ground, that tire will have a tendency to rotate, which will pull on the steering tie rod and send forces to the steering wheel.
What isn't mentioned is that if you're braking, then the wheel on the other side also has the same force applied to it; only the difference between the two forces is what attempts to back-drive the steering system.
Personally, I prefer the smoother and more isolated steering feel of a traditional recirculating-ball system, but then again, I'm not the type of driver who likes fast cornering.
You'd loved DIRAVI like on old Citroën CXes then. Instead of a big spring in the Danfoss valve between the steering column and rack it had a little gearbox with a kind of "dogbone link" joining the two, that got pushed from side to side if there was a difference between the rack position and steering column position to push the valve. Then there was a kind of heart-shaped cam that pushed the steering wheel back to the centre, with a spring pressing against it controlled by hydraulic pressure from a speed sensor on the gearbox. The faster you went the harder it pressed the spring until at 70mph you could barely move the steering wheel but the slightest pressure would steer quite quickly.
Until you got used to its incredibly sensitive response (about 1.5 turns lock-to-lock) you tended to drive in zig-zags like you were tacking a dinghy up the road, but once you did get used to it nothing ever felt as precise or comfortable. I've driven some incredibly "sporty" cars, "cost as much as a house" end of the market cars, and none of them got close to the CX for steering feel.
The earlier GS and GSA had inboard front disc brakes on the side of the gearbox, allowing them to be massive while also allowing the tall skinny tyres (145SR80, about 150mm wide) to be absolutely centred on the kingpin, boresighted on the middle of the contact patch. They had incredible handling, so sharp and responsive, and the non-powered steering was as light as any modern car at parking speeds.
The equalizing brake force from the other side sounds good until you factor in things like ride height differences from worn suspension or imperfect roads. Those and other transient forces disturb that left to right balance. Weird things like bump steer start happening when left to right measurements are off.
I've never driven a car with that kind of suspension, does the design still use caster to self-center the steering, or will the tires stay roughly where you point them even if you let go?
Yes, you have to have caster or the car would be very difficult to drive. I had a VW bug with a worm gear steering box that was going bad. It would almost keep the wheels wherever you put them and it was scary to drive. Think about how you let the steering wheel slip as the wheels return to straight when you turn onto a cross road, you had to return the wheels to straight yourself.
Rear wheel drive cars also do it. The caster on a car mimics that of the wheel of a shopping cart. Having the pivot axis be at a slight angle relative to the direction your travelling makes the wheels trail behind that axis.
It does tend to be more apparent in front wheel drive cars, perhaps it's the weight of the motor? It's really important to get right in motorsport, as it denotes the characteristics of the car when you've oversteered. A car with correctly set caster will "self steer" itself back to straight without any driver input, and it will guide the car while oversteered in a way that's balanced with the direction the car's actually heading rather than where it's pointing (if you're intending to be sideways, like in drifting).
This is a great example of the illusion of explanatory depth [1]
You read the title and think "D'oh obviously traction", then you see the first picture in the article and think "Yep, obviously flatter tyres because traction", then you read a little more and think "Wait, what do they mean by flat?", ...
... and then it just keeps going deeper and deeper into this rabbit hole you never considered before and barely even noticed. You realize you didn't know shit.
The explanation ends up being steering feedback forces. Now I wonder if we can have deeper wheels again with modern electric motor power steering.
There’s a section on aerodynamics that explains why for any vehicle but especially EV’s can benefit. They give an example that flat wheels improve a model S coefficient of drag by 12%.
> The explanation ends up being steering feedback forces.
.... which, is used to communicate traction status back to the driver:
> The ability of forces to feed back to the driver meant there was significantly more “feel” for what the tires were doing and where the limits of adhesion were. (from the article)
> This is felt as kick-back to the driver and if it’s bad enough can rip the wheel out of your hands. Some of you may have had that experience in the past.
It can also break the driver's thumb, if the thumb is on the inside of the rim. If you're driving over rough terrain, you're well advised to keep your thumbs on the outside of the rim. This is true even at low speed. I once had to pull a car up onto a normal-sized curb and did so at low speed. Doing so definitely kicked the wheel.
I was taught to do this in open-wheel racing. Thumbs stick straight up rather than gripping inside the wheel. And on bigger crashes, completely let go of the wheel as quickly as possible.
And, counter-intuitively, get off the brakes! This returns/angles the nose of the car up, which can be the difference between life or death if colliding head-on into a larger object (like a deer).
What a great article! The world is absolutely full of things that are carefully designed around very real engineering constraints that almost none of us know about or ever notice. I always appreciate when a writer can bring me into a new world that I didn’t know anything about and show me the care and attention to detail that I would otherwise have never seen.
The flatness in this case is the outer surface of the aluminium rim. And as a rim enthusiast, I can agree that the modern flatness is less appealing than compared to those in the past.
Deep dish on the old M5 was pretty classy looking, as will the Dodge Charger msg wheels with the curve. It’s too bad the deep dish got all bro-dozer crazy.
I do very much enjoy watching “Kid Stance” videos on YouTube if you want to see a really brilliant creative guy make some AMAZING custom kid ride on toys…warning: addictive!
I would have enjoyed this but didn't understand it. I think the main problem is that I didn't understand what they meant by tyres "being flat" so the rest of it was impossible to grok.
It's not about the tires, it's about the wheels (maybe calling them "rims" makes the connection).
The parts of the suspension the wheel turns on are pushed out towards the center of the contact patch on newer cars to reduce the forces that feed back to the steering wheel. The different steering system used on older cars benefited from those larger forces (because the systems didn't have good feedback).
It did fail to define some terms. Also, it would have been nice to show on the diagrams the direction of the forces involved. It's a bit difficult to visualize precisely.
The timeline of this development exceeds the timeline of my own experiences since the 90's.
I've always driven cars with rack and pinion steering while wheels went from something like a typical 185-65x15 to 245-40x18. So, wheels are larger and the profile is much smaller (more rim and less rubber between the car and the road).
Higher power warrants bigger brakes and bigger brakes warrants larger rims but for the average car rims have grown way oversized. Many cars have the space to take rims that are 2-3 inches smaller than what comes as standard.
My anecdotal and average empirical results is that cars with wide rims and little rubber mostly seem to reduce comfort, increase noise, and make the steering very susceptible to unevenness, slopes and grooves of roads and layers of snow and ice and thus requiring constant steering response from the driver. I've had both kinds and the difference is huge, and exaggerated by bad road conditions that we find on our roads. On my older vehicles with a higher and narrower tyre profile I barely have to steer at all but just keep my hand relaxed on the wheel while the car ploughs pretty much through whatever in a direct line. Of course, I keep the wheel geometry of all my cars well-aligned so they shouldn't wander around.
My car is on 225/40/18, has no floating behaviour, and just the right amount of feedback still to feel what happens on the front wheels, whether it's wheel placement, movement, gripping/slipping... It's an absolute joy to drive, whether on long journeys or spiritedly.
> just keep my hand relaxed on the wheel while the car ploughs pretty much through whatever in a direct line
I would avoid small potholes still but that's basically my feeling on that car. I did slightly bend a rim once when running through a pothole I did not see, and the car ploughed through as described.
I recall reading an article a couple of months ago about steering, feedback, and suspension geometry design. It rang very true to my subjective experience that many car suspensions are designed for "comfort" (vs "sporty"), which results in a lack of relevant direct feedback, which makes the car uneven and floaty, like you're somehow disconnected from the road, and still suffer from bumpiness as you have to rely on indirect cues to compensate, which makes for increased latency and overcorrection.
I wish I could find this article again, IIRC it all comes down to one angle/offset, which you can't really fix by tuning geometry because it's basically baked in the suspension design.
EDIT: it's related to that one[0], but was more detailed regarding that part:
> To make matters worse, the suspension geometry often further compromises steering feel in favor of things like putting less load into tie-rods
It's the wide tire contact patch and not the big rims that are causing most of the problems you describe. This is typically papered over with tons of steering assist and geometry that favors minimal feedback in order to alleviate the propensity of wide tires to be greatly impacted by changes in road shape. This steering solution feels numb and disconnected from the road which is a common complaint with modern cars. The wide tires that are at the root of the problem are a key element of modern car performance so they're not going anywhere.
Additionally, if you move the wheel surface far enough from the center of the tire you can get more room for wheel bearing and axle shaft hardware without increasing the size of the wheel bolt circle and bore though this isn't a big consideration in a lot of applications as there is ample space either way.
in order to figure out what this article is saying, I have to learn a lot of terms, and I don't think it's going to be that astonishing or "aha!" so it doesn't seem worth it. The positive scrub ratio measured along the kingpin axis from the kingpin center... if only I knew what a deep dish wheel was as opposed to a flat wheel...
you need to afix another point in your picture. Imagine a basic wheel mounted on the end of a solid axle. Now imagine that you made the axle shorter and replaced the wheel hub with a cone ("deep-dish") that has the tire mounted on the rim at the wide end of the cone. Did you change anything other than angular momentum (I guess I should say polar moment)?
if you want to say, "you can't use a cone like that because there needs to be a hinge on the axle at this point for the wheel to steer-turn" then we've arrived at the reason for the limit on deep dishes? or if it's some other reason, it still doesn't seem that hard to describe.
what I'm really saying is, the geometric concepts could be taught more simply without the all terminology. My older brother raced cars that he fixed and modified himself, so I grew up basically in a mechanic's shop. That was a long time ago so it's fine if terminology and concepts have changed, but I have a big head start over the average person and I found the article annoyingly incomprehensible
I’m going through this experiment myself. I have some et20 (+20mm offset wheels) in a car that had 45mm offset wheels from the factory. Meaning the wheel center is 25mm further out than stock. However, the new wheel is also wider, so is not all on one side.
The steering is definitely different, especially because I also have tires that are 3 inches wider than the factory ones. The car is harder to keep straight if the ground is uneven because it wants to pull in all sorts of directions. I also don’t like how at full lock the outer wheel drags on the ground.
But at this width the closest I can get is an offset of +35mm, any higher and the wheel touches the control arm, and at 40 it would probably hit the springs.
Talking to some track guys seems like they are still faster with a wider track than with lower scrub and told me to not worry about it, but I still have my concerns.
Related question: Why must brakes be inside the wheels rather than inboard on the axle? Why not weld disks onto the axle inboard of the wheels and put the brakes there? That would make more room inside the wheels.
Of course on undriven front wheels it wouldn't work because there is no axle, but in front-wheel-drive cars there is one. The brakes could be inboard of the CV joint, no?
See the inboard brakes on 60's Jaguars - Sure, the unsprung weight and improved handling is nice but they are much harder to maintain because 1. you have to lift the car to see if they are worn and 2. if you have to repair a caliper it is almost easier to drop the entire rear suspension than to try to dig the caliper out while everything is on the car.
1. Brakes generate massive amount of heat and need cooling. There is a ton of airflow down at the wheels, some wheels are even designed to direct more airflow to the brakes.
2. Because changing brakes down at the wheels takes 20 minutes with the proper tools. If you move them inboard and affix the rotor to the axle you would significantly increase labor time and cost in replacing the brakes.
Both good reasons but I'd argue #2 is not considered by the engineering in practical reality. Have you seen the lengths some manufacturers require people to go through for things like a simple battery replacement? headlight bulb change? Or even in some cases the hoops to jump through for an oil change? There's some extreme examples out there of each, I heard horror stories from my friend who used to do automotive mechanical work (alternators only reachable by dropping the engine) and there's countless stories over at reddit's /r/Justrolledintotheshop
Yes, I was previously a mechanic. Truth is even the worst battery replacements (behind the bumper), headlight bulb changes (remove the bumper), still take less than ~45 minutes to complete. Alternators are not generally considered a wear item so they can be difficult to replace if the engineers where not friendly to the mechanics.
Brakes are a wear item, they eat themselves by design and need to be replaceable. Moving them inboard from the wheel does not have any significant benefits, but many downsides.
With regenerative braking on EV's it could possibly make more sense to move the brakes inboard, but there is already all the space in the wheels for brakes to fit, so I don't really see the benefit of moving them.
Because then you'd get a huge amount of torque between the brakes and the wheel, esp through the CV joint it'd be unnecessarily brutal. On the back wheels it could be possible, on the front (where most of the braking is) unlikely.
I’m not sure about that. Most cars can stop way faster than they can accelerate. The differences in force would be even more extreme for front wheel drive cars where the weight transfer allows for more grip on the front wheels during braking compared to accelerating or peeling out.
If the wheel is sliding the torque on the wheel will be lower than if the tires were grippier. I guess the comparison is if braking is high (de)-acceleration than the engine. I'm thinking your idea has a lot of the same stresses as engine braking.
I can't really understand the author's (and apparently some designers') fetish about "deep dish" wheels. If a flat wheel allows better technical solutions and even improves aerodynamics, I'm all for flat wheels! Hell, even Formula 1 cars (which used to have the "deepest" wheels ever) use hubcaps since this season (https://the-race.com/formula-1/gary-anderson-how-f1s-new-whe...). Maybe that will make "flat wheels" sexy? We will have to wait and see...
There are a lot of car things that have no functional benefit, but exist because they used to mean something (but not anymore) or are useful at racing speeds but not at normal ones, or are simply traditional.
One I find particularly amusing is the Ford Mustang Mach-E, a fully battery-powered vehicle, has the ability to play fake engine noise through the cabin speakers because some drivers think engine noise is a feature of "real cars".
It’s not even an electric car thing - my Focus ST came from the factory with a little sound pipe thingy from the engine to the cabin to make it feel more racy. When I bought it used it was disconnected, which is fine, because the MBRP 2.5” cat back exhaust already installed is about 3x louder than stock.
I’m pretty sure BMW was doing it too when they started going all turbo and losing the song of the NA.
I drove a BMW x5 a couple of years back, and it piped fake engine noise into the cabin. IIRC, it was a petrol v6/v8, so was quite capable of making it's own sound, so the whole thing was pointless - but worse, the fake engine noise sounded totally fake! Honestly, I felt pretty silly with it enabled!
There a lot of things that make a car feel faster, and giving them higher displacement engines and louder exhausts has more disadvantages than it’s worth for most people.
You can get the same experience with slightly more cabin noise (that doesn’t annoy your neighbours), a longer first gear, kickdown pedal, etc.
It’s kinda like Coke Zero. If you can get 95% of the same experience, why opt for the sugar?
AFAIC a higher rubber shell slightly helps with suspension.
Thin wheels help with aquaplaning/hydroplaning (strongly) and slightly with reducing consumption.
Most wide wheels available to consumers are thick, so that is a tradeoff that happens with the new design, although I might mix up physical ratio, price and street legality, due to having only looked at one car.
Some cars have a virtual ball joint on the bottom of the hub to get around the ‘the brakes are in the way’ issue. Two separate arms with two more inboard ball joints act the same as one arm with the joint much further out.
I have a 1985 VW Vanagon camper. Mechanically, it's a POS with 99.9% NLA parts. It has 16" truck tires. Before that, it had properly weight-rated 14" trailer tires (the owner before had under-spec, unsafe passenger car tires on it.) The 16" are much easier to find and cheaper than the 14". Geometry-wise, the OD isn't excessively different that before because it's a massive, strong "pillow" between surfaces and the OD of rim. It's when you get to the point where you can't hop a curb at low speed without worrying about wrecking the rims that there's a problem with low profile tires. There always exists a high enough speed over a large enough obstacle that will cause mechanical damage to rims. If you want to drive a super car with perfect aerodynamics everyday, don't use driveways with any incline to them, don't get near to curbs, and don't drive anywhere with potholes.
The challenge is how much optimization for efficiency vs. durability vs. cost manufacturers want to or are ordered to sacrifice.
The kind of person who doesn't understand that trailer tires have some pretty substantial tradeoffs in car use is not going to be loading their classic van heavily enough and then driving it fast enough to have issues with some random car tires that don't match the OEM weight rating.
One question I've had: why are car brakes inside the wheel at all? Is it only ease of servicing? Putting the brake disks on the shaft before the suspension would make wheels lighter and allow positioning the kingpin much further out.
I tried to google for an explanation, but only found hits about brakes problems.
It is called inboard brakes. I think there is a chance they make a comeback with electric cars because the braking system can be zero maintenance due to regen and the half shafts are already very strong due to the powerful motors.
The Autopian is a great car site. It was set up by some Jalopnik writers (david tracy and jason torchinsky). As well as "normal" car articles they love techy/offbeat/unusual aspects of cars and aren't afraid to publish it.
I'm reading this article and the whole time I'm thinking, my 1998 Jeep Cherokee XJ has completely flat wheels, and then I get to the very bottom:
> [Editor’s Note: Not all designers prefer dished wheels. Some commenters were wondering why the Jeep JK/JL Wrangler, which has an old-school steering box instead of a rack and pinion setup, has such flat wheels. As far as I know, this is largely a styling decision. -DT].
So, it also applies the the XJ limited wheels too:
As an i.reddit mobile user, it retains the old iphone/mobile optimized css of reddit. There are actual html buttons with minimal js nonsense and not a to of a useless whitespace. On desktop I'm a fervent old.reddit user and sincerely hope they don't deprecate the, (imo better, more info dense), style.
The kind of people who get rims repaired rather than just buying new (no doubt based on some hand-wavy BS about safety from someone who makes a margin on the rims they sell) don't buy new rims.
The BBC's "More or Less" pointed out some of the claims about tyres being a major contributor to air pollution are exaggerated. One of the claims was based on the total amount of wear from tyres as weight, without considering that most of that wear is made of very large particles that remain on the ground.
Some of the data confirming the hypothesis may be from looking at studded snow tires. They tear up a lot of crap in the air if you use them on roads that aren't covered in ice.
The link I gave has serious sources, and "remains on the ground" is a bit vague, a large amount of air pollution is just dust from the road and elsewhere raised up by cars
TL;DR: Wheels contain the brakes, so they need space inside for the brakes. Just inside the wheel is part of the steering pivot mechanism. Constraints around the optimal design of these systems prevent the classic 'domed' wheel construction.
Does anybody actually enjoy this type of type of SEO content?
Stuffed with filler words to the max. Maybe there is an answer to the title somewhere on the page. But the way it is written, it just stole my time until I gave up after a few paragraphs of filler content. First sentence:
Have you ever wondered why designers show
sketches of concept cars with massive deep dish wheels, but
when those cars actually make it to production the wheels
end up being fairly flat?
No. I just followed a link "Why car wheels are so flat these days" and was interested in the answer.
Compare that to a classic essay "A plan for spam" by Paul Graham:
I think it's possible to stop spam,
and that content-based filters are the way to do it.
That's the type of content I would like to see on HN.
If it was 2022 style SEO content, PG's essay would have started with "Have you ever wondered why you get so much spam into your inbox these days and why that spam is so terribly boring, sprinkled with typos and ads, often full of images and links, and what you could do to get rid of it?". Shudder.
Which was in part a reference to some questions on the comment threads from other articles in which a designer sketched some car ideas on that site.
So, you may not have wondered that, but someone on the site wondered that, and another writer on the site, who, granted, has an background in engineering car suspensions, not writing, wrote this article in response.
I think you’re being overly harsh. This is a post on a website for car enthusiasts. Car enthusiasts do in fact look at artist’s renders of cars because they’re genuinely into car culture. I think it’s an effective hook.
If you just want a straightforward answer then Google it and perhaps Google can find the right snippet that you can ingest in 8 seconds.
This does not seem to be a SEO content pushed out by some content farm to me (although I don't have expertise in the area being written about) the article seems like there was quite a bit of work put into it; I think probably the writer is just not as succinct as you would like.
Mechanical engineer here, this article could have more detail and I'd have read it. The translation from nuts and bolts and rods and links in the suspension to the intangible but apparently important (for selling cars) "feel" is fascinating. It's sometimes idiotic - "make an Audi Q7 feel like a Porsche" required a movable central connection in the rear suspension for some rear wheel steer (but just using the existing play/travel) as well as a hydraulic then (v2) electric doo dah to counteract the tilt and keep the boat of a car level through turns. There's no "point" to this - it just let's them sell a souped up big SUV at 911 prices and make money hand over fist.
I'm not even a car person but this article wasn't laboring the point.
I confused as to why the feel of a car driven at road speeds isn’t a “real”/valuable/relevant selling point in road cars. That’s a huge factor in my car purchases, and it’s the thing I remember most about my old cars.
Because that's not something that is typically checking in "test drives" nowadays. I was once yelled at by the Renault saleswoman for braking too hard during a test drive, even though I told here that I'm about to perform an emergency stop. She had us return to the dealership. I happily bought a Focus instead, the very next day, after a proper test drive.
But don't get me started on them providing a rear-disc-brake Focus for the test drive even though the trim level I was interested in had rear drums. Had I driven the drum model, I would not have bought it. But I acknowledge that I'm an outlier, who actually cares about how the vehicle handles and accelerates and brakes and takes potholes and how noisy it is at highway speeds and how it fares in a cross wind. The common, typical "test drive" doesn't cover any of those aspects anymore.
Hang on, so multi tonne vehicles are designed with the rolling stock equivalent of anaerodynamic stability managed by black boxes?
I guess this is situated for latency but more likely installation and loom cost controls, close to the rear axle therefore more exposed to moving accident damage and at least to my casual reading of owner enthusiast fora unknown to educated owners and the public - rather like the Eurofighter Typhoon?
How can such designs pass DMV / MOT tests with inherent rolling instability in failure mode?
Or is there failsafe?
Edit: I should have said multi tonne vehicles intended by design to be driven fast and at limits including load limits.
It's called "dynamic chassis control" - it keeps the chassis level by pushing back against the torque forces in the sway bar. The equivalent vw or audi will have body roll. Most vehicles have a "u-shape" anti sway bar coupling the right and left side - the car still leans, just not as much. It's not a safety feature or a thing to keep all four wheels on the ground. It's a mechanical device that uses energy (from the engine) to counteract the torque in the sway bar for the purpose of keeping the chassis level.
I start to think these days one has to write like this and fill the page with 2k words of fluff before getting to the point if one hopes the website to show up in Google.
I recently struggled a lot with a technical problem. I searched and searched and I couldn't find a solution. Then I discovered a solution myself and I created a short blog-style tutorial how to resolve it.
As far as I know the only one on the Web, but does it show in Google search results when one searches for exact phrase or quite rare keywords used? No way, I've added it to Google, Google scanned it, and that's it.
Searching for the problem you find my forum posts where I ask (unsuccessfully) for help about it and maybe few more people doing the same,nothing more.
Perhaps instead of writing my blog entry for humans (state the problem, describe a solution). I should've written it for Google bot in a format of:
- State a problem
- why do we have this problem
- what is the history of stuff we have the problem with
- a personal story how I saved my dog while working on the solution
- at the very end one sentence that hints at a solution (don't just give it away! Make 5 pages talking about it instead!)
Try github gist or creating a stackoverflow question and answering it, I find that even short snippets are indexed well on whitelisted platforms like these.
Well it's a random thing thrown at me on HackerNews... I don't care that much about car wheels to invest several minutes into reading about this completely random fact. Either it tells me relatively quickly, or I stop caring.
Huh? Didn’t get that vibe at all. This article is actually just what I was looking for to begin learning about steering systems, from a technical but high level, before doing some maintenance work on a truck.
For what it's worth, I hate the fluff. But the information buried within was very interesting. Unfortunately, with a single dominant gatekeeper to all the web's content, that gatekeeper dictates how people will write.
That said, I understand Google's position. Back in the WildWildWest days of the WorldWideWeb, Google made the change from preferring keyword-based text to preferring written-for-humans text. But the target humans seem to those who read for love of reading, as judged by lit majors. Now I've been teased since kindergarten for my love of reading, but as a professional I want concise and terse, not an overabundance of anecdotes and adjectives. But the lit majors who influenced the post-2008 spider algorithms correctly for the time influenced a preference for the later.
Hopefully sometime Google will figure out that technical texts should be keyword based, and literary texts should be for-humans, whatever that is deemed to mean. And Google might provide either a feature to choose the algorithm, or more likely, try to guess based on heuristics.
Papers have an abstract with a summary of the results then go on for pages explaining the long road to them. Maybe that could be a format to mimic and appease both kind of audiences: people with no time or interest to learn all the details and enthusiasts that want to read everything about the subject.
While I agree with the basic sentiment, this article is the type of article I will usually just skim fairly quickly, skipping sections if they aren't connected to the title.
Agree. I was both interested enough to read the whole article AND really annoyed at the fluff. (“let me explain”, “of course”, “we’ll get back to that”) Bleh.
Given my OCD this drives me nuts because I can’t look at a wheel to get a sense if it’s low on air pressure anymore. I always get nervous thinking it’s gone flat and needs fixing.
Here's their writeup on the electric F-150 - keep scrolling on that page, and look at the kind of depth and detail they get into: https://www.theautopian.com/the-2022-ford-lightning-is-just-...
The site is a gem.