5 ms·

Also considering that it's policy UPS (maybe others?) to turn off the engine at every stop, and starting a vehicle is fuel intensive in an ICE vehicle

brk 3y ago
I don't think that is correct, many vehicles now have the auto start/stop as a way of meeting emissions requirements.
LgWoodenBadger 3y ago
If it's so intensive, why is auto-stop/start such a common feature on many vehicles? Especially since it seems to improve city-cycle mpg ratings...
- ekleraki 3y ago
  [flagged]
  - housemusicfan 3y ago
    This is false.
    - ekleraki 3y ago
      Can you find a link that shows that ICE / non hybrid and non ev make up the majority of cars with automatic start and stop?
  - flangola7 3y ago
    There's many 100% ICE vehicles that shutdown at stops.
    - ekleraki 3y ago
      Mostly means the majority and by construction allows for exceptions.
  - MisterTea 3y ago
    My 2022 CRV ICE has this by default. You can turn it off but on by default every time you start the car (US law or something.)
    - ekleraki 3y ago
      Again, mostly means majority and allows for exceptions.
  - lostapathy 3y ago
    This is demonstrably false. Even new Jeep Wranglers and Gladiators come with auto start/stop, and those are about as far removed from hybrids as it gets.
    - ekleraki 3y ago
      “Mostly” includes exceptions.
      - lostapathy 3y ago
        My point was that most vehicles include this feature, even those you’d least expect it on.
  - shiftpgdn 3y ago
    The motor stops at TDC under compression and then fires the spark plugs to restart, reducing wear on the starter.
    - mynameisash 3y ago
      For others that -- like me -- have no clue what TDC is, I did a quick search[0]: > Top dead center, sometimes referred to as TDC, is the point in which the piston in the number one cylinder position of your engine is at its highest point on the compression stroke. [0] https://www.wikihow.com/Find-Your-Engine%27s-Top-Dead-Center-(TDC) https://www.wikihow.com/Find-Your-Engine%27s-Top-Dead-Center...
- Kon-Peki 3y ago
  Auto stop/start requires some (mostly minor) modifications to the engine, as well as updated software so that it is used only in “ideal” conditions. And the engine shutdown is done in a way that makes it quick and easy to restart. I’m not sure, is it even possible to use these systems on diesel motors?
  - gambiting 3y ago
    Of course - I've had a diesel Nissan Qashqai with a start stop system all the way back in 2013. Never had any issues with it.
- taeric 3y ago
  This is an amusing place where most of the advancement was probably in the starter. The same thing that lets you have a small charger for your laptop has helped get a smaller starter that won't drain after a few starts. There is a lot of work that goes into starting an engine.
eptcyka 3y ago
It takes less fuel than most people think.
- taeric 3y ago
  This is almost certainly one of those things where the tech has moved on. It definitely used to use a fair bit of fuel to get started. Not so much anymore. Probably also depends on where you are? I'd imagine colder climates need to keep the engine running.
  - bluGill 3y ago
    Even way back when it used a lot of fuel to get started, it only took a few seconds of engine off the make up that fuel.
    - taeric 3y ago
      I've had cars need jumping from too many starts draining the battery, though. So, mayhap it was less the fuel and more the battery/starter?
      - eptcyka 3y ago
        Modern cars will disable stop/start if the battery is low. My car won't even use the start/stop feature if the HVAC is operating at a 100% of it's capacity.
ska 3y ago
> to turn off the engine at every stop, and starting a vehicle is fuel intensive in an ICE vehicle This is backwards. The whole point of these systems is that it costs more in fuel at idle than it does to stop and restart. Lots of "pure" ICE cars have this now with some smarts about operating temperature, battery etc. Idling was worse on carbs, sure, but even with injectors your fundamental problem is you don't have enough airflow, and you counteract that by richening the mix so you don't stall.
jyap 3y ago
Not actually true. https://en.m.wikipedia.org/wiki/Start-stop_system https://en.m.wikipedia.org/wiki/Start-stop_system
- taeric 3y ago
  Great link and a good resource for folks curious on this. I had posited that it was likely changes in the starter getting more efficient that has caused this to become more common. However, the article makes it clear that it is largely changes in how things are powered in the car. The specific point about the belt being used to power AC and such is likely the largest factor on why this is slowly going out. (And why it is more common in hybrids, since they had to be designed to power all systems without the belt.) Is a very interesting case study in what software folks would call "tech debt."

brk 3y ago

I don't think that is correct, many vehicles now have the auto start/stop as a way of meeting emissions requirements.

LgWoodenBadger 3y ago

If it's so intensive, why is auto-stop/start such a common feature on many vehicles? Especially since it seems to improve city-cycle mpg ratings...

ekleraki 3y ago
[flagged]
- housemusicfan 3y ago
  This is false.
  - ekleraki 3y ago
    Can you find a link that shows that ICE / non hybrid and non ev make up the majority of cars with automatic start and stop?
- flangola7 3y ago
  There's many 100% ICE vehicles that shutdown at stops.
  - ekleraki 3y ago
    Mostly means the majority and by construction allows for exceptions.
- MisterTea 3y ago
  My 2022 CRV ICE has this by default. You can turn it off but on by default every time you start the car (US law or something.)
  - ekleraki 3y ago
    Again, mostly means majority and allows for exceptions.
- lostapathy 3y ago
  This is demonstrably false. Even new Jeep Wranglers and Gladiators come with auto start/stop, and those are about as far removed from hybrids as it gets.
  - ekleraki 3y ago
    “Mostly” includes exceptions.
    - lostapathy 3y ago
      My point was that most vehicles include this feature, even those you’d least expect it on.
- shiftpgdn 3y ago
  The motor stops at TDC under compression and then fires the spark plugs to restart, reducing wear on the starter.
  - mynameisash 3y ago
    For others that -- like me -- have no clue what TDC is, I did a quick search[0]: > Top dead center, sometimes referred to as TDC, is the point in which the piston in the number one cylinder position of your engine is at its highest point on the compression stroke. [0] https://www.wikihow.com/Find-Your-Engine%27s-Top-Dead-Center-(TDC) https://www.wikihow.com/Find-Your-Engine%27s-Top-Dead-Center...
Kon-Peki 3y ago
Auto stop/start requires some (mostly minor) modifications to the engine, as well as updated software so that it is used only in “ideal” conditions. And the engine shutdown is done in a way that makes it quick and easy to restart. I’m not sure, is it even possible to use these systems on diesel motors?
- gambiting 3y ago
  Of course - I've had a diesel Nissan Qashqai with a start stop system all the way back in 2013. Never had any issues with it.
taeric 3y ago
This is an amusing place where most of the advancement was probably in the starter. The same thing that lets you have a small charger for your laptop has helped get a smaller starter that won't drain after a few starts. There is a lot of work that goes into starting an engine.

eptcyka 3y ago

It takes less fuel than most people think.

taeric 3y ago
This is almost certainly one of those things where the tech has moved on. It definitely used to use a fair bit of fuel to get started. Not so much anymore. Probably also depends on where you are? I'd imagine colder climates need to keep the engine running.
- bluGill 3y ago
  Even way back when it used a lot of fuel to get started, it only took a few seconds of engine off the make up that fuel.
  - taeric 3y ago
    I've had cars need jumping from too many starts draining the battery, though. So, mayhap it was less the fuel and more the battery/starter?
    - eptcyka 3y ago
      Modern cars will disable stop/start if the battery is low. My car won't even use the start/stop feature if the HVAC is operating at a 100% of it's capacity.

ska 3y ago

> to turn off the engine at every stop, and starting a vehicle is fuel intensive in an ICE vehicle This is backwards. The whole point of these systems is that it costs more in fuel at idle than it does to stop and restart. Lots of "pure" ICE cars have this now with some smarts about operating temperature, battery etc. Idling was worse on carbs, sure, but even with injectors your fundamental problem is you don't have enough airflow, and you counteract that by richening the mix so you don't stall.

jyap 3y ago

Not actually true. https://en.m.wikipedia.org/wiki/Start-stop_system https://en.m.wikipedia.org/wiki/Start-stop_system

taeric 3y ago
Great link and a good resource for folks curious on this. I had posited that it was likely changes in the starter getting more efficient that has caused this to become more common. However, the article makes it clear that it is largely changes in how things are powered in the car. The specific point about the belt being used to power AC and such is likely the largest factor on why this is slowly going out. (And why it is more common in hybrids, since they had to be designed to power all systems without the belt.) Is a very interesting case study in what software folks would call "tech debt."