Chapter 1 and Chapter 2 (which make up Volume 1) is repeatedly mentioned to be special and fundamental to the rest of the book series.

Well maybe if you started on book 1 chapter 1, you’d know how to read these books.

Why didn’t you start with the fundamentals book Volume 1?

You just jumped directly into complex combinatorics and then complained that the material was too difficult.

I’ve begun to pay for Kagi.com

I wouldn’t say that it “blows my mind” or anything, but simply that it seems to work as expected (which is more than what I can say for Google). There’s also a “Fediverse” button on Kagi.com, so it can search lemmy.world (and more??).

https://youtu.be/7csgV2CuKNg?si=q9vOaUlW9SRY2rsD

Like, it happens. No other car maker has videos like this.

So we know Tesla’s have it. What we don’t know is if it’s a UI issue or a physical malfunction. Given what I know about Tesla’s shitty UI design, it very well could be user interface issues.

Right here sir, where all the dead people are from obvious safety glitches.

Tesla cars can’t even reliably open their doors when they catch on fire or sink into a lake. Electronic locks, electronic touchscreen shifter, electronic death traps.

You can’t even turn on the windshield wiper without dumb electronics getting in the way of stupid Tesla’s.

Your 2005 Saturn didn’t have electronic locks that failed when the 800Volt battery pack touches water.

The number of Tesla drivers getting locked in and dying is disturbing. Who puts a safety critical electronic only lock tied to the main battery pack? Tesla, that’s who.

Fire? Your electronic locks fail and you die. Water? Same same. Etc. Etc.

Because insufferable Tesla fanbois have for literally fucking years told us that touchscreen controls are better.

No they aren’t you dumb fucks. When you cant feel reverse vs feeling drive, people will get confused. And when you get confused on a 3 ton 600horsepower vehicle, people fucking die.

Go shove the shitty defense of touchscreen controls up all your collective asses. Tesla fanbois are insufferable.

Anyway, human computer interaction folks (HCI) have been talking about these issues for literally a decade. Tesla vehicles are prone to sudden unintended acceleration. Tons of people have gotten locked inside a Tesla unable to escape. Etc. Etc. Tons of terrible UI issues and human control issues. It’s well known at this point.

At least you can still feel the rotating Jeep shitty gear selector.

Touchscreen controls on a Tesla have no feel or feedback. It’s a touchscreen.

I’m more inclined to blame Tesla’s electronic locks and confusing manual override before blaming the windows though

Quick, do you know which panel to remove to find the non-electronic manual override in a Tesla? Car is sinking fast and the electronics just shorted out from the lake.

But sure, tons of bad design decisions here. It’s hard to blame any one of them as the singular cause. If Tesla had easier to use manual override doors instead of electronic locks, if the windows could be broken, if the screen wasn’t a confusing touchscreen mess, etc. Etc. Lots of factors and all are the cause.

https://www.msn.com/en-us/money/companies/a-mistake-in-a-tesla-and-a-panicked-final-call-the-death-of-angela-chao/ar-BB1jAkIW

Within minutes of saying her goodbyes, she called one of her friends in a panic. While making a three-point turn, she had put the car in reverse instead of drive, she said. It is a mistake she had made before with the Tesla gearshift. The car had zipped backward, tipping over an embankment and into a pond. It was sinking fast. Could they help her?

The problem wasn’t the glass.

The problem was using wtf touchscreen controls to shift between drive and reverse. Mrs. Chao confused the two then died.

Shitty UI kills another person. Tesla fucking up basic UI design is the real villain here.

A lot of the CVTs I was thinking about when I wrote that post were eCVTs like the Prius Prime.

I didn’t realize that eCVT for Prius Prime is very different than… other… CVTs. There’s probably more kinds of CVTs out there than any other transmission.

Prius Prime has two powerful electric motors (!!) for spinning two different parts of the planetary gear system, +1 ICE engine (so 3x total powered inputs) to the power split device. Toyota calls it eCVT, because CVT is emulated by computers controlling the 3x inputs. When one of the electric motors spins in reverse, it increases the effective gear ratio of the other parts of the power-split device, leading to a feeling of instant torque that’s powered by the electric motor.

Honda Accord’s eCVT is completely different, as I’ve discovered through discussion later down with another poster. Honda’s Hybrid is closer to a pure electrical system and… they say eCVT for some insane reason but its just an electric motor really.

So its different than what other car manufacturers called a CVT. I didn’t realize how many kinds of CVTs there were today when I wrote that post.

Agreed. I edited a bit about Hybrids / Electric motors in there while you were typing that response up.

Hybrid Engines really change the game, as do full electrics. I still am convinced that a gearbox is superior by the way (ie: Toyota Prius or Ford Escape designs, as well as Porsche Tycan for a full EV). But electric engines have many more “tricks” available that remove the need of a manual clutch, wet clutch, or other needs of older ICE designs.

ICE still is overall cheaper. But if Hybrid becomes the new standard, then manuals are fully dead. These eCVT / planetary gear system magic is really incredible… and no need for a clutch (or wet-clutch) either.

I personally feel like overpowered EVs will be seen as wasteful, especially because we’ve reached the limitation on how cheap Li-ion can get. Cheaper batteries are possible with future chemistries (Sodium-ion, Silicon+Li-ion , etc. etc.) but not dramatically so. I don’t think it will be possible to scale up mass production of the complex chemical processes needed to convert acid from mountains into Lithium. And recycling of Lithium remains fraught with problems.

Of course, I could be wrong and maybe these problems will be solved soon. But for the near future, assuming the environmental costs of Li-ion remain roughly the same as now, there’s a bigger need to shrink down battery/motors and therefore use gears to handle a wider range of driving speeds.

The cheapest material moving forward will remain steel. Therefore any “steel-based” solution (like a gearbox) will remain the king of overall efficiency and effectiveness of car designs. Copper, Lithium, Cobalt, Silicon, Sodium… many other metals can build up more complex behaviors (EVs), but ugggh. They’re just not as cheap or effective as what steel can do.

Dropping 250lbs and removing the torque converter (~2% loss alone) will do more for overall fuel efficiency for your car than anything those automatic transmissions can do.

Yeah, I get that computers + improved automatic modes of transmission control (ex: CVTs or Dual Clutch Transmissions) can improve engagement times. And the removal of the wet-clutch/slushbox of automatic transmissions grossly improves efficiency. But these units are still heavier in practice than a dumb, manual clutch.

I don’t think any automatic transmission beats a manual in efficient driving yet. Because weight is king. Automatics (at least, DCTs and CVTs) are finally reaching the response times of a manual transmission by having more direct connection of accelerator pedal to the engine… but the weight issue, cost-issue are still there.

At least modern transmissions basically never brake down anymore. (CVTs, Dual Clutch, and more are all basically going to last the whole lifetime of a typical car).

That being said, these eCVT designs from Hybrid cars (Prius Prime, Ford Edge) are pretty incredible, and are far superior to anything a manual can do.

But for pure ICE, I’m not quite sure if even the most advanced automatic today can beat me in manual. Its more about how the electric-motor interacts with the system that we finally have a way for computers to beat me. But without an electric motor, I’m reasonably confident that my manual driving is still overall better than an automatic.

My point is that if you’re a manual driver and you don’t care about the 0-60 time, then all you gotta do is slow down the clutch release so that the clutch spends… I dunno, half-a-second engaging the engine, rather than quarter-a-second or faster. Slowing down the clutch-release (erm, re-engaging the engine) smooths out the acceleration, is easy on your parts, and barely affects your acceleration times.

Its only a problem in 0-60 drag races when you’re literally trying to beat everyone else off the line. But if you’re just doing day-to-day relaxed driving… just take it easy. Its not like you’re flooring the car anyway.

I personally always like to try to time the RPM decrease such that I can instantly lift off my leg from the pedal as quickly as possible, because I like having a little skill minigame when driving. (Matching RPMs with the speed of my car for smoother shifts, and more instant engagements). But that’s really not necessary.

Just apply the gas after the clutch re-engages to minimize wear/tear. Any slippage you have for RPM-matching with tires will be miniscule if there’s no engine power. I’m over 100k miles on my car, no clutch replaced yet. So I know what I’m doing is gentle driving for the parts.

I’ve seen manual Fords with a little trick where it holds the revs at the speed for the next gear up, just for a second or so, to make it easier to get a perfect gear change. However, even then an automatic is far better for maintaining acceleration, and therefore more accelerating more efficiently.

0-60 drag races are not a common use case in daily driving. You gear shift to 2nd before making a 15mph turn. You downshift to 3rd when entering a 25mph zone. You shift to 5th (or whatever your last gear is) as you enter the highway.

Otherwise, you’re rarely touching the clutch or gearbox. Sure, a 0-60 hits all gears and requires 5 shifts to be done smoothly, but that’s rare.

Because I’m a human, and I can see the road… I can see that the ~15mph turn is coming up. So I can be already in 2nd gear before the turn comes up. This is useful for engine braking anyway. Then I’m in the correct gear for the turn, and out of the turn. Hitting the proper gear long-before the automatic (DCT, Wet-clutch, or CVT) would ever know about the turn.

This is not an aggressive turn for racing. Racing would likely require heel-toe, a difficult maneuver as I’ve described above. But for daily driving, just predicting “where the car will be” in 10 seconds and getting the gear shifts done ahead of time is really what you’re doing. If you’ll be in 2nd gear soon, might as well get that over with and shift slightly before its needed (5 seconds or so ahead).

Manual will always be cheaper. Even CVTs cost more.

A Manual clutch is just a drum-brake (like object) controlled by a a reversed 3rd pedal (brake-like system engages when the pedal is released. While pushing the pedal releases the clutch, its “backwards”) that allows the engine to engage with the transmission system. The gearbox has no computers, just one hydraulic line (only those associated with the 3rd pedal), and unlike a disc-brake its barely used so the drum-like system (which is even cheaper than disc brakes and lasts for 100,000+ miles easily).

The important thing is this “how do you deal with disconnecting the engine from the tires” problem. When 3rd gear is 5000 RPM for your speed, 4th gear might be 4000 RPM (depending on your gearbox of course). A Manual clutch just has the user push on the drum-brake like clutch (releasing the engine, allowing it to spin freely), then you slowly release the clutch, which causes this “brake” to slowly connect the engine with the tires (tires speed up while engine slows down).

Manual drivers get very good at this, and add engine speed / accelerate on downshifts (ex: going from 4000 RPM to 5000 RPM as you go from 4th gear to 3rd gear), you can just apply the accelerator thereby adding engine speed to assist the clutch in matching RPMs for a smooth transition.

Alternatively, manual drivers can heel-toe: apply the accelerator, brake, and clutch simultaneously. Not only is the accelerator helping push the RPM from 4000 RPM and upwards with engine… the brakes are slowing down the car bringing the “target RPM” down to 4500 RPM. So the manual driver can assist in both directions thanks to the use of all three pedals. This technique is called heel-toe because your left-leg controls the clutch, while your right-toe hits the brakes, while the right-heel hits the accelerator, and your heel/toe does different things to help match the RPMs to the Tires.

Modern automatics are:

1. Traditional Wet Clutch – A Wet Clutch uses a highly viscous liquid (aka: the torque converter) that is “always slipping”, no matter the conditions of the car. This means that your car is now always smooth, but the “slush” can take a while before the fluid spins-up to the speeds that matches the engine-with-the-wheels. This is the longest running technology, and someone pointed out that modern wet-clutches like ZF8 are considered quite good. So yeah, “always be disconnected” and use liquid viscosity to help match RPMs as needed.

2. CVTs – unpopular due to the weird noises, but Subaru WRX has shown that its a superior system with relatively cheap manufacturing. A computer controls two hydraulic systems push upon the chain, changing the effective-gear-ratio smoothly. Early models were unreliable and broke, and some bad CVTs still exist out there. But after a few years, all CVTs are long-life and reliable. Subaru has also changed it so that modern CVTs make noises closer to traditional engines, as it turns out that the human ear of an advanced driver is constantly evaluating the engine, so our ear-training is important part of the driving experience.

3. Dual Clutch – A computerized manual transmission. Computers still can’t do all of the manual application that I described above. But… if you add two clutches, and switch between even-gears and odd gears. (ex: Clutch#1 controls gear 1-3-5-7, and Clutch#2 controls 2-4-6-8), then you can switch to the 2nd clutch, and then perform a computerized switch while disconnected. This cheats at the “slippage” problem, but cheating means cheaper assembly and better performance.

In all three cases, modern automatics are heavier, require more parts, more assembly. Reliability is getting better however, and as computers minimize engine slippage the transmissions are having less stress applied to them in general.

https://www.youtube.com/watch?v=jofycaXByTc

I’ve decided to do some research on eCVT. I was surprised at its actual implementation. Toyota Prius, Ford Escape, and probably Honda Accord does this.

Its basically planetary gear magic. A computer can control two or three inputs, while the outputs are hooked up to the wheels of the car. By changing the speed of the variable input (likely the electronic engine)… the effective gear ratio of the “constant” input (likely the ICE engine) is modified. In the most extreme case, the variable input runs backwards to have the “overdrive” gear ratio.

It seems like the Honda Accord is a planetary gear eCVT system. Planetary gears are always so cool, I didn’t realize that a CVT could be implemented with one (albeit with a hybrid vehicle where you have 2 or more powered inputs).

EDIT: it appears that you are correct. Honda’s Hybrid system is different than what I’m familiar with (which is what the above video demonstrated).

https://youtu.be/QLUIExAnNcE?si=7JzkfL8GfUUoFnbK

So you’re right with regards to Honda Accord Hybrid. Very interesting. Its always surprising to me how different car companies are with their implementations.

I’m well aware of the larger torquebands across wider RPMs of electric motors vs ICE motors, especially the high torque available at 0 RPM. But that doesn’t change physics or chemistry.

Porsche Taycan isn’t a supercar, and it has this high/low gear / Two-speed transmission for its EV, because at higher RPMs even an EV will run out of torque, and it becomes a good idea to convert RPM vs Torque through the use of a gearbox. Gearboxes / Transmissions have been used for a hundred years. They are among the most sophisticated parts of a modern car, and are made with cheap steel and highly automated manufacturing today.

Every motor will have a limit to their useful torquebands. EVs have the widest torque vs RPM in existence ever, but even the biggest motors and biggest EVs have problems.

This is complicated by the fact that Hybrids are far smaller electric-motors with far less battery power than the pure EVs like a Porsche Tycan. As such, the incredibly popular Toyota Prius Prime opts instead for a proper CVT transmission. And I’m willing to bet that Prius Prime 2024 is getting a better driving experience in practice.

Furthemore: there’s something to be said about sophistication of dumber / simpler metals. Steel is found everywhere. Trading cheap steel for Lithium, Copper, and Cobalt sounds like a bad idea to me in general. I guess that copper/lithium is lighter than Steel so saving on weight is helpful, but there’s some crazy bad environmental problems associated with these rarer and more complex metals.