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How does a defeat-able non-essential feature shorten a vehicle’s lifespan?

HWR_14 5y ago
If it's a feature required by the government to be road legal, it's likely not run and/or pass emissions testing if it's not working. And it's a point of failure written by people who are bad at software. Alternatively, computer control of real world systems (e.g. acceleration and braking) can lead to actual accidents, totaling the vehicle. There was that lady who claims her Tesla's software caused a crash, and, without commenting on if that is true, it's plausible.
stefan_ 5y ago
Here is a thing that happens: many countries have more or less comprehensive regular vehicle inspections. If your car is showing a warning light or reports an error on the standardized interface, that can cause you to fail the inspection. What a warning light is shown for is at the discretion of the manufacturer though. One example is Anti-lock braking (ABS), which they made mandatory in 2004. If you bought a car without it in 2003 and have it inspected in 2013, no problem. If you bought a car with ABS in 2004 and the controller for it breaks in 2008, you will fail the inspection - even though your braking is no worse than the 2003 car (ABS was wisely designed to fail safe..).
- aunty_helen 5y ago
  The point of abs isn’t to improve your braking system. It’s to stop you from panicking in an accident situation, locking up the front wheels and losing the ability to steer. Abs actually very slightly reduces the stopping potential of your brake system. But being able to steer and control your car is a bigger benefit under these circumstances.
  - stefan_ 5y ago
    Now think it through. What happens if a wheel locks up? Right, it loses all stopping power. I certainly agree that you want ABS, it's just to illustrate the pitfalls it creates when you have these additional systems. You can tell much the same story around emissions controls; newer cars pass stricter emissions standards and require extra parts and technology to achieve them.
    - mnemnc 5y ago
      > Now think it through. What happens if a wheel locks up? Right, it loses all stopping power. That‘s not true. Going in a straight line, blocking wheels will stop you in less distance than with active ABS. However ABS allows you to brake and go around an obstacle without losing control of your vehicle.
      - throwaway525142 5y ago
        I think the friction of wheels is lower when the wheels lock up vs when they go with the speed of the road. From Wikipedia[1]: > Kinetic friction, also known as dynamic friction or sliding friction, occurs when two objects are moving relative to each other and rub together (like a sled on the ground). The coefficient of kinetic friction is typically denoted as μk, and is usually less than the coefficient of static friction for the same materials.[40][41] [1]: https://en.wikipedia.org/w/index.php?title=Friction&oldid=1054585720#Kinetic_friction https://en.wikipedia.org/w/index.php?title=Friction&oldid=10...
      - jjav 5y ago
        > That‘s not true. Going in a straight line, blocking wheels will stop you in less distance than with active ABS. Most certainly not. The sliding coefficient of friction of a tire is quite a bit less than the static coefficient of friction. Shortest stopping distance is achieved by keeping the tire rolling, just on the very edge of lockup, for the entire braking distance. Early ABS systems had slow pulse cycles and couldn't control wheels individually, so a good driver could outbrake them but the ones from the last 20 years are quite good. ABS is one rare example of a safety technology that doesn't have much drawbacks. Very much unlike newer technologies like lane assist and self braking, which have benefits but also clear drawbacks. Even for ABS though, there are edge case dangers that a non-ABS car wouldn't have (like ice mode disabling brakes when not on ice). There's no magic answer with tehcnologies. Every time a system increases complexity, it increases failure mode potential as well.
- alphabettsy 5y ago
  Fair enough, but that’s not what was brought up and I don’t know why you would want a vehicle without ABS. Since most people don’t know how to panic stop without ABS I think it’s reasonable that it cause an inspection failure. I’m not aware of a jurisdiction where you would fail an inspection because your rear park assist or lane departure warning didn’t work.

If it's a feature required by the government to be road legal, it's likely not run and/or pass emissions testing if it's not working. And it's a point of failure written by people who are bad at software. Alternatively, computer control of real world systems (e.g. acceleration and braking) can lead to actual accidents, totaling the vehicle. There was that lady who claims her Tesla's software caused a crash, and, without commenting on if that is true, it's plausible.

stefan_ 5y ago

Here is a thing that happens: many countries have more or less comprehensive regular vehicle inspections. If your car is showing a warning light or reports an error on the standardized interface, that can cause you to fail the inspection. What a warning light is shown for is at the discretion of the manufacturer though. One example is Anti-lock braking (ABS), which they made mandatory in 2004. If you bought a car without it in 2003 and have it inspected in 2013, no problem. If you bought a car with ABS in 2004 and the controller for it breaks in 2008, you will fail the inspection - even though your braking is no worse than the 2003 car (ABS was wisely designed to fail safe..).

aunty_helen 5y ago
The point of abs isn’t to improve your braking system. It’s to stop you from panicking in an accident situation, locking up the front wheels and losing the ability to steer. Abs actually very slightly reduces the stopping potential of your brake system. But being able to steer and control your car is a bigger benefit under these circumstances.
- stefan_ 5y ago
  Now think it through. What happens if a wheel locks up? Right, it loses all stopping power. I certainly agree that you want ABS, it's just to illustrate the pitfalls it creates when you have these additional systems. You can tell much the same story around emissions controls; newer cars pass stricter emissions standards and require extra parts and technology to achieve them.
  - mnemnc 5y ago
    > Now think it through. What happens if a wheel locks up? Right, it loses all stopping power. That‘s not true. Going in a straight line, blocking wheels will stop you in less distance than with active ABS. However ABS allows you to brake and go around an obstacle without losing control of your vehicle.
    - throwaway525142 5y ago
      I think the friction of wheels is lower when the wheels lock up vs when they go with the speed of the road. From Wikipedia[1]: > Kinetic friction, also known as dynamic friction or sliding friction, occurs when two objects are moving relative to each other and rub together (like a sled on the ground). The coefficient of kinetic friction is typically denoted as μk, and is usually less than the coefficient of static friction for the same materials.[40][41] [1]: https://en.wikipedia.org/w/index.php?title=Friction&oldid=1054585720#Kinetic_friction https://en.wikipedia.org/w/index.php?title=Friction&oldid=10...
    - jjav 5y ago
      > That‘s not true. Going in a straight line, blocking wheels will stop you in less distance than with active ABS. Most certainly not. The sliding coefficient of friction of a tire is quite a bit less than the static coefficient of friction. Shortest stopping distance is achieved by keeping the tire rolling, just on the very edge of lockup, for the entire braking distance. Early ABS systems had slow pulse cycles and couldn't control wheels individually, so a good driver could outbrake them but the ones from the last 20 years are quite good. ABS is one rare example of a safety technology that doesn't have much drawbacks. Very much unlike newer technologies like lane assist and self braking, which have benefits but also clear drawbacks. Even for ABS though, there are edge case dangers that a non-ABS car wouldn't have (like ice mode disabling brakes when not on ice). There's no magic answer with tehcnologies. Every time a system increases complexity, it increases failure mode potential as well.
alphabettsy 5y ago
Fair enough, but that’s not what was brought up and I don’t know why you would want a vehicle without ABS. Since most people don’t know how to panic stop without ABS I think it’s reasonable that it cause an inspection failure. I’m not aware of a jurisdiction where you would fail an inspection because your rear park assist or lane departure warning didn’t work.