4 ms·

One of the most frightening moments of my early life was when the accelerator peddle got stuck (actually one of the connecting rods) going into a roundabout, fa

One of the most frightening moments of my early life was when the accelerator peddle got stuck (actually one of the connecting rods) going into a roundabout, fairly recently after passing my driving test. I couldn't figure out why I was speeding up even when breaking hard. But somehow I managed to maintain control and put the gear into neutral - and then sat at the edge of the roundabout with the engine screaming at full throttle before I figured out what was wrong and turned off the ignition. Wouldn't want to be in a Cybertruck with that happening.

brandonagr2 3y ago
You would want to be in a Cybertruck, when you press the brake pedal it auto overrides the accelerator pedal. Being in a Cybertruck with a stuck accel pedal is way safer than in a traditional truck
- danparsonson 3y ago
  Except it's all fly by wire so you're relying on the software to be bug free and I'd honestly rather trust physics.
  - lucianbr 3y ago
    There is no "physics", unless you're relying on falling fast without a parachute or something like that. In this case you're relying on mechanics to be bug free as opposed to software. To imply that any car is designed and built in such a way that it can only fail if physics itself fails is rather arrogant. There are comments here in the thread pointing to the long lists of bugs with non-drive-by-wire cars. Mechanics may well be easier to design correctly and test, sure. But get out with "physics".
    - danparsonson 3y ago
      > To imply that any car is designed and built in such a way that it can only fail if physics itself fails is rather arrogant You're putting words in my mouth. All I'm saying is that direct physical connections between things are much more reliable and straightforward than software connections between things. Of course no system is perfect.
      - Too 3y ago
        Source? This very case itself, of the accelerator pedal coming loose and jamming, was in fact a mechanical problem. Other comments above have more examples of stuck accelerator wires and more. Mechanics wear and tear and allow for human override and human error, software introduces complexity. Both have their own set of issues, neither are perfect, one can’t say either of them is inherently more reliable.
      - lucianbr 3y ago
        There is not a direct physical connection between the brake pedal and the brakes, or the acceleration pedal and the... not even sure what this would be. The n admission valves on the cylinders? Unless you consider "direct" as "passing through 5-50 different parts that each has an effect on the next in the chain", which is the definition of indirect. I'm not putting words in your mouth, I'm pointing out you're using the wrong words. You're neither relying on "physics", which would mean a failure of the system would be caused by a failure of "physics", meaning something like the Maxwell's ecuations turn out to be wrong, nor on "direct connection", unless the brake pedal is directly pushing on the brake rotor, which is obviously false. Of course there's no problem with saying you'd rather rely on mechanics or hydraulics than electronics or software. Though, to use words your way, tesla is not relying on "software", but on "math".
    - deleted 3y ago
      [deleted]
  - kube-system 3y ago
    Fly by wire throttles have been commonplace in cars since the early-to-mid 00s.
- helsinkiandrew 3y ago
  I was more referring to its power and size, you need to figure out that your still accelerating when you've released pressure on the accelerator and you need to switch pedals to break. Where are you going to be after half a second of maximum acceleration in a 6600lb cybertruck?
  - tnmom 3y ago
    0-60 time is 2.6 seconds, or 10.32m/s^2 if it’s evenly distributed. So from zero you’d be doing 11.5mph in 0.5s (and travelled a little over four feet). But importantly, it looks like this is more of a ratchet effect… so if your pedal is stuck at 100%, it’s because you pressed it that far (even if intending it to be momentary). That’s not something you’d normally do in a parking lot full of nuns, you’re probably on a highway with some time to react and press the brake. My guess is that’s why we haven’t seen a tragic accident out of this.
- IshKebab 3y ago
  Yeah except it has a 0-60mph time of 2.6 seconds. You're probably already travelling at at least 20 so you have 1-2 seconds to figure out what's going on before you crash. Good luck.
- matja 3y ago
  Until the brake pedal falls off as well
  - anticensor 3y ago
    Stopping is better than unavoidable runaway acceleration
- rootusrootus 3y ago
  > Being in a Cybertruck with a stuck accel pedal is way safer than in a traditional truck I'd bet there isn't a current truck on the market that doesn't cut the throttle when you hit the brake. Basically all cars now.
- kube-system 3y ago
  Traditional automakers have been programming their vehicles to work exactly the same way for a decade+, ever since the Toyota stuck accelerator debacle. My last two cars both ignored throttle input when the brake was depressed.
echoangle 3y ago
What car was this in? I was always told that the brake of a modern car is much stronger than the engine so you can always come to a stop, even with a stuck accelerator
- mrguyorama 3y ago
  While the breaks physically will be ABLE to overcome the engine in anything that isn't a dodge hellcat, if the peddle is stuck to the floor and the engine is at full throttle, you won't have much or any vacuum boosting effects! You will have to quite literally STAND on the brake peddle like the bad old days, and a lot of people driving today have never experienced unassisted braking.
- deleted 3y ago
  [deleted]
- blake1 3y ago
  In most modern cars, there is a pressure booster in the power brake system, enabling braking force that can overcome the engine’s horsepower and quickly stop the car. But they are designed to continually maintain the braking force for a limited amount of time—30 seconds or so—after which this boosting ability is depleted. Once that happens, braking must be fully supplied by muscle power via the mechanical backup. This is challenging if the engine is stuck in a wide open throttle (WOT) state, because the driver must overcome the cars weight in addition to the engine. For a small car like a Toyota Corolla, this requires a few hundred pounds of downforce on the pedal. For a large 300hp SUV, this could require a thousand pounds of downforce. As you said, the brakes can bring the car to a stop, but the car will start reaccelerating if the engine isn’t shut off. (Sorry for mixing physical units.)
- topspin 3y ago
  While it is the case, by design and typically by regulation, that brakes have more braking force on paper than the engine and drivetrain can produce, in the real world it is not so straightforward. ICE engines have active heat rejection and conventional brakes don't. So ultimately in any prolonged fight between an engine and brakes the engine will win. Hot brakes have a lower coefficient of friction. This is the brake "fade" experienced on long downhill runs or heavy use, such as while towing heavy loads. In extreme cases brake pad outgassing, brake pad glazing and boiling brake fluid, all a consequence of heat, will degrade brake power. Traditionally vacuum assist is used to amplify brake force in passenger cars. The vacuum reserve is, however, finite and little vacuum is available from an engine with a stuck open throttle. When the throttle is even partially open and the engine RPM is kept low (such as when fighting it with the brakes) the vacuum drops severely. When boost runs out brake force is greatly reduced. This all changes in heavier vehicles where more robust systems are employed, such as compressed air brakes with large pressure reserves. Some vehicles have enough power to overcome the brakes on driven wheels. Some vehicles have "low range" gearing that can also easily overcome the brakes. The situation described by helsinkiandrew was probably a combination of brake fade that emerged while fighting the engine and lack of brake boost due to low vacuum because the throttle was somehow stuck. But there isn't enough information to say for certain.
iknowstuff 3y ago
FWIW, even if the accelerator pedal is stuck or misread in the Cybertruck, the brake pedal immediately overrides any input from it and stops accelerating.
- MBCook 3y ago
  So I’m going to wildly speculate here: I’m guessing most CTs have sold to big Tesla fans who already had Teslas. I’m going to assume those kind of fans also like one-pedal driving (many people do). So if you’ve been using one-pedal for years you’re used to releasing the accelerator stopping you. Could the driver who hit a pole have stopped themselves with the brake? Yes. If they were used to one-pedal for years, would they have thought of that? In a split-second panic scenario perhaps not. I know millions of people love one-pedal and many (most?) electric cars have done version of it. But I wonder if stuff like this has been studied. How well to people used to it handle using the brake in a panic if they don’t often drive two pedal mode/cars? I’d love to know the results of such a study.
  - hacker_88 3y ago
    If one was aware what was happening, they would be able to stop/Slow but lifting the brake would immediately cause the car to accelerate . This would be instantaneous acceleration enough to cause damage before you could hit the brakes at which it would stop.
  - yazaddaruvala 3y ago
    Single pedal driving still requires me to use the brake pedal often. In reality, there might be a 3-5x reduction to brake pedal usage. That still means on any given trip, every 5th stop sign/red light will require break pedal usage. If anything the single pedal driving causes me to let off of the accelerator earlier than I normally would in an ICE car, and therefore I have more time to react with the break pedal if needed. I doubt I'm unique in these things.
    - zormino 3y ago
      I rarely hit the brake pedal in my car at all with one pedal driving. In fact I'd say 80% of drives I don't hit it at all, and the rest i might use it once or twice. I'm sure I'd still hit the brake in an emergency since it's so ingrained in me from driving normal cars for so long, but I'm not sure how long that will be true for, especially for new younger drivers that have really only driven EVs.
cameronh90 3y ago
Stuck throttles used to be quite a common problem in the pre-ECU days. I've had two cars that had a stuck throttle in the past, both where the accelerator cable connects to the throttle body on the top of the engine. In both cases, lubing it up solved the problem and it never reoccurred. It is a bit of a shocking thing to happen, but with a manual it's instinctive to just jam the clutch down. What worries me about modern cars, in particular electrics, is the lack of any kind of kill-switch. Motorbikes have them, cars used to just have an ignition switch, but now everything from the ignition to the accelerator pedals is electric. Wouldn't it be a good idea to have a switch that kills the car if all else fails?
- HaZeust 3y ago
  Shifting the car into neutral is your best bet, as well as a pumped parking/emergency brakes. However, I will always believe that turning secondary brakes into a button/lever was a bad idea.
  - e44858 3y ago
    In some cars the transmission is also controlled electrically.
    - HaZeust 3y ago
      Don't buy a car that can't manually go into neutral. Ever.
  - callalex 3y ago
    In cyber trucks shifting to neutral requires a tap and a gesture on the touch screen. It’s a really great and safe idea.
    - GhostVII 3y ago
      Putting shifting controls on the screen was dumb for many reasons, but doesn't really cause a problem in this case - the cybertruck will disable the accelerator when you hit the brakes, accomplishing the same thing as putting it into neutral.

brandonagr2 3y ago

You would want to be in a Cybertruck, when you press the brake pedal it auto overrides the accelerator pedal. Being in a Cybertruck with a stuck accel pedal is way safer than in a traditional truck

danparsonson 3y ago
Except it's all fly by wire so you're relying on the software to be bug free and I'd honestly rather trust physics.
- lucianbr 3y ago
  There is no "physics", unless you're relying on falling fast without a parachute or something like that. In this case you're relying on mechanics to be bug free as opposed to software. To imply that any car is designed and built in such a way that it can only fail if physics itself fails is rather arrogant. There are comments here in the thread pointing to the long lists of bugs with non-drive-by-wire cars. Mechanics may well be easier to design correctly and test, sure. But get out with "physics".
  - danparsonson 3y ago
    > To imply that any car is designed and built in such a way that it can only fail if physics itself fails is rather arrogant You're putting words in my mouth. All I'm saying is that direct physical connections between things are much more reliable and straightforward than software connections between things. Of course no system is perfect.
    - Too 3y ago
      Source? This very case itself, of the accelerator pedal coming loose and jamming, was in fact a mechanical problem. Other comments above have more examples of stuck accelerator wires and more. Mechanics wear and tear and allow for human override and human error, software introduces complexity. Both have their own set of issues, neither are perfect, one can’t say either of them is inherently more reliable.
    - lucianbr 3y ago
      There is not a direct physical connection between the brake pedal and the brakes, or the acceleration pedal and the... not even sure what this would be. The n admission valves on the cylinders? Unless you consider "direct" as "passing through 5-50 different parts that each has an effect on the next in the chain", which is the definition of indirect. I'm not putting words in your mouth, I'm pointing out you're using the wrong words. You're neither relying on "physics", which would mean a failure of the system would be caused by a failure of "physics", meaning something like the Maxwell's ecuations turn out to be wrong, nor on "direct connection", unless the brake pedal is directly pushing on the brake rotor, which is obviously false. Of course there's no problem with saying you'd rather rely on mechanics or hydraulics than electronics or software. Though, to use words your way, tesla is not relying on "software", but on "math".
  - deleted 3y ago
    [deleted]
- kube-system 3y ago
  Fly by wire throttles have been commonplace in cars since the early-to-mid 00s.
helsinkiandrew 3y ago
I was more referring to its power and size, you need to figure out that your still accelerating when you've released pressure on the accelerator and you need to switch pedals to break. Where are you going to be after half a second of maximum acceleration in a 6600lb cybertruck?
- tnmom 3y ago
  0-60 time is 2.6 seconds, or 10.32m/s^2 if it’s evenly distributed. So from zero you’d be doing 11.5mph in 0.5s (and travelled a little over four feet). But importantly, it looks like this is more of a ratchet effect… so if your pedal is stuck at 100%, it’s because you pressed it that far (even if intending it to be momentary). That’s not something you’d normally do in a parking lot full of nuns, you’re probably on a highway with some time to react and press the brake. My guess is that’s why we haven’t seen a tragic accident out of this.
IshKebab 3y ago
Yeah except it has a 0-60mph time of 2.6 seconds. You're probably already travelling at at least 20 so you have 1-2 seconds to figure out what's going on before you crash. Good luck.
matja 3y ago
Until the brake pedal falls off as well
- anticensor 3y ago
  Stopping is better than unavoidable runaway acceleration
rootusrootus 3y ago
> Being in a Cybertruck with a stuck accel pedal is way safer than in a traditional truck I'd bet there isn't a current truck on the market that doesn't cut the throttle when you hit the brake. Basically all cars now.
kube-system 3y ago
Traditional automakers have been programming their vehicles to work exactly the same way for a decade+, ever since the Toyota stuck accelerator debacle. My last two cars both ignored throttle input when the brake was depressed.

echoangle 3y ago

What car was this in? I was always told that the brake of a modern car is much stronger than the engine so you can always come to a stop, even with a stuck accelerator

mrguyorama 3y ago
While the breaks physically will be ABLE to overcome the engine in anything that isn't a dodge hellcat, if the peddle is stuck to the floor and the engine is at full throttle, you won't have much or any vacuum boosting effects! You will have to quite literally STAND on the brake peddle like the bad old days, and a lot of people driving today have never experienced unassisted braking.
deleted 3y ago
[deleted]
blake1 3y ago
In most modern cars, there is a pressure booster in the power brake system, enabling braking force that can overcome the engine’s horsepower and quickly stop the car. But they are designed to continually maintain the braking force for a limited amount of time—30 seconds or so—after which this boosting ability is depleted. Once that happens, braking must be fully supplied by muscle power via the mechanical backup. This is challenging if the engine is stuck in a wide open throttle (WOT) state, because the driver must overcome the cars weight in addition to the engine. For a small car like a Toyota Corolla, this requires a few hundred pounds of downforce on the pedal. For a large 300hp SUV, this could require a thousand pounds of downforce. As you said, the brakes can bring the car to a stop, but the car will start reaccelerating if the engine isn’t shut off. (Sorry for mixing physical units.)
topspin 3y ago
While it is the case, by design and typically by regulation, that brakes have more braking force on paper than the engine and drivetrain can produce, in the real world it is not so straightforward. ICE engines have active heat rejection and conventional brakes don't. So ultimately in any prolonged fight between an engine and brakes the engine will win. Hot brakes have a lower coefficient of friction. This is the brake "fade" experienced on long downhill runs or heavy use, such as while towing heavy loads. In extreme cases brake pad outgassing, brake pad glazing and boiling brake fluid, all a consequence of heat, will degrade brake power. Traditionally vacuum assist is used to amplify brake force in passenger cars. The vacuum reserve is, however, finite and little vacuum is available from an engine with a stuck open throttle. When the throttle is even partially open and the engine RPM is kept low (such as when fighting it with the brakes) the vacuum drops severely. When boost runs out brake force is greatly reduced. This all changes in heavier vehicles where more robust systems are employed, such as compressed air brakes with large pressure reserves. Some vehicles have enough power to overcome the brakes on driven wheels. Some vehicles have "low range" gearing that can also easily overcome the brakes. The situation described by helsinkiandrew was probably a combination of brake fade that emerged while fighting the engine and lack of brake boost due to low vacuum because the throttle was somehow stuck. But there isn't enough information to say for certain.

iknowstuff 3y ago

FWIW, even if the accelerator pedal is stuck or misread in the Cybertruck, the brake pedal immediately overrides any input from it and stops accelerating.

MBCook 3y ago
So I’m going to wildly speculate here: I’m guessing most CTs have sold to big Tesla fans who already had Teslas. I’m going to assume those kind of fans also like one-pedal driving (many people do). So if you’ve been using one-pedal for years you’re used to releasing the accelerator stopping you. Could the driver who hit a pole have stopped themselves with the brake? Yes. If they were used to one-pedal for years, would they have thought of that? In a split-second panic scenario perhaps not. I know millions of people love one-pedal and many (most?) electric cars have done version of it. But I wonder if stuff like this has been studied. How well to people used to it handle using the brake in a panic if they don’t often drive two pedal mode/cars? I’d love to know the results of such a study.
- hacker_88 3y ago
  If one was aware what was happening, they would be able to stop/Slow but lifting the brake would immediately cause the car to accelerate . This would be instantaneous acceleration enough to cause damage before you could hit the brakes at which it would stop.
- yazaddaruvala 3y ago
  Single pedal driving still requires me to use the brake pedal often. In reality, there might be a 3-5x reduction to brake pedal usage. That still means on any given trip, every 5th stop sign/red light will require break pedal usage. If anything the single pedal driving causes me to let off of the accelerator earlier than I normally would in an ICE car, and therefore I have more time to react with the break pedal if needed. I doubt I'm unique in these things.
  - zormino 3y ago
    I rarely hit the brake pedal in my car at all with one pedal driving. In fact I'd say 80% of drives I don't hit it at all, and the rest i might use it once or twice. I'm sure I'd still hit the brake in an emergency since it's so ingrained in me from driving normal cars for so long, but I'm not sure how long that will be true for, especially for new younger drivers that have really only driven EVs.

cameronh90 3y ago

Stuck throttles used to be quite a common problem in the pre-ECU days. I've had two cars that had a stuck throttle in the past, both where the accelerator cable connects to the throttle body on the top of the engine. In both cases, lubing it up solved the problem and it never reoccurred. It is a bit of a shocking thing to happen, but with a manual it's instinctive to just jam the clutch down. What worries me about modern cars, in particular electrics, is the lack of any kind of kill-switch. Motorbikes have them, cars used to just have an ignition switch, but now everything from the ignition to the accelerator pedals is electric. Wouldn't it be a good idea to have a switch that kills the car if all else fails?

HaZeust 3y ago
Shifting the car into neutral is your best bet, as well as a pumped parking/emergency brakes. However, I will always believe that turning secondary brakes into a button/lever was a bad idea.
- e44858 3y ago
  In some cars the transmission is also controlled electrically.
  - HaZeust 3y ago
    Don't buy a car that can't manually go into neutral. Ever.
- callalex 3y ago
  In cyber trucks shifting to neutral requires a tap and a gesture on the touch screen. It’s a really great and safe idea.
  - GhostVII 3y ago
    Putting shifting controls on the screen was dumb for many reasons, but doesn't really cause a problem in this case - the cybertruck will disable the accelerator when you hit the brakes, accomplishing the same thing as putting it into neutral.