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My dad's Subaru has saved a total of 7 minutes of runtime thanks to this misfeature over the past year, in exchange for many extra cycles on the starter. What a

by aftbit 3y ago

My dad's Subaru has saved a total of 7 minutes of runtime thanks to this misfeature over the past year, in exchange for many extra cycles on the starter. What an absolutely silly idea.

RandallBrown 3y ago
He can turn it off if he wants. I've saved considerably more time (maybe like 20-30 minutes?) in just a few months of having my new Subaru.
- ultrarunner 3y ago
  It resets itself back on (by law) every time you restart the vehicle. A couple days ago mine failed to restart itself, instead shifting into neutral (!) and rolling partially into the intersection I had intended to pull out into. It wouldn't shift into park because it wasn't "on" (?) but also wouldn't turn "on" (!?) as traffic started to barrel down on me. I'm honestly not sure what sequence of pushing the "on/acc/start/off" button, the "park" button, and "drive" button got it back running, but eventually I was able to go. It was a somewhat stressful experience, but I guess I saved ~10-15 seconds of idling trying to leave work?
  - deleted 3y ago
    [deleted]
  - giantg2 3y ago
    "It resets itself back on (by law) every time you restart the vehicle" That's what internet searches and fuse pullers are for. "but I guess I saved ~10-15 seconds of idling" That's where the calculations get tricky. There's usually a time limit for which it's less efficient to stop the engine (about 4-7 seconds). So to calculate fuel savings, you actually should only count idle fuel rate times the number of seconds above that cutoff, then you also have to account for less efficient stops under that rate (maybe just subtract them from your seconds above so you get a net seconds beyond breakeven mark). I'm not sure any the systems track it that way, it's just how much overall time the car spent in the stopped mode.
    - ultrarunner 3y ago
      I used to just turn my car on and off when I wanted it on and off. Now I have to do internet searches and figure out how to modify (break) some black box system to keep it from creating minor safety situations or inadvertently undervolting the stupid touch screen so my stereo no longer works (requiring a turn-it-off-and-back-on-again that I … you know, can no longer do).
- Incipient 3y ago
  Even 1h every few months. My car consumes about 1lt/hour idle, and at $2/lt for fuel, thats a saving of $2/few months. Or about $10/year. Stop-start just doesn't seem worth it. Hybrids where you can travel kilometres in stop-start traffic over the course of an hour every day without using the engine at all, now that seems super worthwhile!
i80and 3y ago
Maybe it's regional? I've been given rental Subarus with this feature and it adds up really fast in my experience -- minutes in a day even. Honestly I think it's pretty cool, and you get a more reliable starter as a bonus.
- steve_adams_86 3y ago
  I guess in a city where you're more stop and go it would add up quickly. We've saved a ton of running time on our Highlander, and I'm content with the feature. Yet when we drive long distances, it's virtually useless. I don't know. Maybe for some people it really is a mis-feature, but I like it.
- huytersd 3y ago
  You get two starters if I’m not mistaken.
- everdrive 3y ago
  Your starter is not more reliable — it’s actually two starters in one: a traditional starter, and then one which handles the special scenario of “auto-start-stop.” I don’t have any reason to believe this is necessarily less reliable, but the starter itself is significantly more complex and expensive. In a fully gasoline vehicle, I think this technology is situational at best. In a hybrid it makes a lot of sense since the engine will normally be stopping much more frequently.
SteveNuts 3y ago
How is that possible (only 7 minutes over a year), he must either not drive very much or live very close to a highway? My commute, the stoplights alone would easily add up to that every day.
- HeyLaughingBoy 3y ago
  It doesn't sound unreasonable to me. There are very few stop lights around here: the closest one is about 8 miles away and the next closest one is at the onramp to the interstate. It's quite easy to visit friends that are 20 miles away and not encounter a single light. Lots of stop signs though.
Night_Thastus 3y ago
Cars with start/stop have significantly more robust starter equipment. It's really a non-issue. If you're idling for more than around 7 seconds at a time, stopping the engine makes sense from a gas perspective.
- Dalewyn 3y ago
  We have a 2021 Subaru Outback. We had to take it in to the dealer for servicing because the car battery died and wouldn't hold a charge. Turns out it was a known problem covered under manufacturer warranty, that the battery was specced too small for Outbacks equipped with idle stop and couldn't handle drawing so much power so often. Incidentally, the properly specced battery and associated parts that would need to be replaced would have cost around $400 if it wasn't covered under warranty.
bmacho 3y ago
In exchange for how many extra cycles?
kube-system 3y ago
Hybrids work differently than start-stop on a gasoline-only car. The vast majority of hybrids don't have or need starters, because they can start by backfeeding power from the drive motor(s).

by aftbit 3y ago

My dad's Subaru has saved a total of 7 minutes of runtime thanks to this misfeature over the past year, in exchange for many extra cycles on the starter. What an absolutely silly idea.

RandallBrown 3y ago

He can turn it off if he wants. I've saved considerably more time (maybe like 20-30 minutes?) in just a few months of having my new Subaru.

ultrarunner 3y ago
It resets itself back on (by law) every time you restart the vehicle. A couple days ago mine failed to restart itself, instead shifting into neutral (!) and rolling partially into the intersection I had intended to pull out into. It wouldn't shift into park because it wasn't "on" (?) but also wouldn't turn "on" (!?) as traffic started to barrel down on me. I'm honestly not sure what sequence of pushing the "on/acc/start/off" button, the "park" button, and "drive" button got it back running, but eventually I was able to go. It was a somewhat stressful experience, but I guess I saved ~10-15 seconds of idling trying to leave work?
- deleted 3y ago
  [deleted]
- giantg2 3y ago
  "It resets itself back on (by law) every time you restart the vehicle" That's what internet searches and fuse pullers are for. "but I guess I saved ~10-15 seconds of idling" That's where the calculations get tricky. There's usually a time limit for which it's less efficient to stop the engine (about 4-7 seconds). So to calculate fuel savings, you actually should only count idle fuel rate times the number of seconds above that cutoff, then you also have to account for less efficient stops under that rate (maybe just subtract them from your seconds above so you get a net seconds beyond breakeven mark). I'm not sure any the systems track it that way, it's just how much overall time the car spent in the stopped mode.
  - ultrarunner 3y ago
    I used to just turn my car on and off when I wanted it on and off. Now I have to do internet searches and figure out how to modify (break) some black box system to keep it from creating minor safety situations or inadvertently undervolting the stupid touch screen so my stereo no longer works (requiring a turn-it-off-and-back-on-again that I … you know, can no longer do).
Incipient 3y ago
Even 1h every few months. My car consumes about 1lt/hour idle, and at $2/lt for fuel, thats a saving of $2/few months. Or about $10/year. Stop-start just doesn't seem worth it. Hybrids where you can travel kilometres in stop-start traffic over the course of an hour every day without using the engine at all, now that seems super worthwhile!

i80and 3y ago

Maybe it's regional? I've been given rental Subarus with this feature and it adds up really fast in my experience -- minutes in a day even. Honestly I think it's pretty cool, and you get a more reliable starter as a bonus.

steve_adams_86 3y ago
I guess in a city where you're more stop and go it would add up quickly. We've saved a ton of running time on our Highlander, and I'm content with the feature. Yet when we drive long distances, it's virtually useless. I don't know. Maybe for some people it really is a mis-feature, but I like it.
huytersd 3y ago
You get two starters if I’m not mistaken.
everdrive 3y ago
Your starter is not more reliable — it’s actually two starters in one: a traditional starter, and then one which handles the special scenario of “auto-start-stop.” I don’t have any reason to believe this is necessarily less reliable, but the starter itself is significantly more complex and expensive. In a fully gasoline vehicle, I think this technology is situational at best. In a hybrid it makes a lot of sense since the engine will normally be stopping much more frequently.

SteveNuts 3y ago

How is that possible (only 7 minutes over a year), he must either not drive very much or live very close to a highway? My commute, the stoplights alone would easily add up to that every day.

HeyLaughingBoy 3y ago
It doesn't sound unreasonable to me. There are very few stop lights around here: the closest one is about 8 miles away and the next closest one is at the onramp to the interstate. It's quite easy to visit friends that are 20 miles away and not encounter a single light. Lots of stop signs though.

Night_Thastus 3y ago

Cars with start/stop have significantly more robust starter equipment. It's really a non-issue. If you're idling for more than around 7 seconds at a time, stopping the engine makes sense from a gas perspective.

Dalewyn 3y ago
We have a 2021 Subaru Outback. We had to take it in to the dealer for servicing because the car battery died and wouldn't hold a charge. Turns out it was a known problem covered under manufacturer warranty, that the battery was specced too small for Outbacks equipped with idle stop and couldn't handle drawing so much power so often. Incidentally, the properly specced battery and associated parts that would need to be replaced would have cost around $400 if it wasn't covered under warranty.

bmacho 3y ago

In exchange for how many extra cycles?

kube-system 3y ago

Hybrids work differently than start-stop on a gasoline-only car. The vast majority of hybrids don't have or need starters, because they can start by backfeeding power from the drive motor(s).