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October 23, 2019 5:45 AM Subscribe
I have been test-driving some new cars this fall. Several of them come with a feature called idle stop.
The cars are designed to shut down if you are idleling more than a couple of minutes. This happens if your foot is on the brake. If you put in park it will idle all day. Also, you can turn this feature off each time you start the car, just not permanentally .
My question: is there any data, anecdotal or othewise, about how much more wear and tear this puts on the starter and battery over the normal life of a car?
The cars are designed to shut down if you are idleling more than a couple of minutes. This happens if your foot is on the brake. If you put in park it will idle all day. Also, you can turn this feature off each time you start the car, just not permanentally .
My question: is there any data, anecdotal or othewise, about how much more wear and tear this puts on the starter and battery over the normal life of a car?
The starter definitely comes into play.
Such systems usually use an AGM or higher-capacity battery, and a stronger starter. I recall when this technology was first rolled out there may also be a slightly different starter design.
posted by MonsieurBon at 5:58 AM on October 23, 2019
Such systems usually use an AGM or higher-capacity battery, and a stronger starter. I recall when this technology was first rolled out there may also be a slightly different starter design.
posted by MonsieurBon at 5:58 AM on October 23, 2019
In most of the cars I've seen, it can be permanently shut off through a combination of buttons, or, more common, using an ODBII code programmer (as in the BMW).
I had the same concern as you, and while I am sure it's been tested and falls within "it's fine and doesn't add too much additional wear and tear", I could not take it shutting on and off in NYC traffic...
posted by niteHawk at 6:08 AM on October 23, 2019 [1 favorite]
I had the same concern as you, and while I am sure it's been tested and falls within "it's fine and doesn't add too much additional wear and tear", I could not take it shutting on and off in NYC traffic...
posted by niteHawk at 6:08 AM on October 23, 2019 [1 favorite]
This feature has been common in European cars for 10+ years. I don't have a link to authoritative data for you, but if these systems didn't work well we'd know by now. The Wikipedia article has some description of the changes in the engine and starter made to support start-stop, with many references. This article also has some description.
BTW, a lot of people hate these things when they first drive them because it feels like the car is sluggish to get going at a green light. But I found after a couple weeks driving one I'd completely adapted to it and never think about it any more. I think I'm unconsciously taking my foot off the brake anticipating the need to go.
posted by Nelson at 6:48 AM on October 23, 2019 [6 favorites]
BTW, a lot of people hate these things when they first drive them because it feels like the car is sluggish to get going at a green light. But I found after a couple weeks driving one I'd completely adapted to it and never think about it any more. I think I'm unconsciously taking my foot off the brake anticipating the need to go.
posted by Nelson at 6:48 AM on October 23, 2019 [6 favorites]
We had a BMW with this feature, and while unnerving to me at first -- especially on the test drive, since they didn't warn us about it before hand! -- I was stunned by how seamless and well thought out it was.
The seamlessness was really shocking. At first, I assumed it would impose a delay on getting going at red lights, but it restarted SO FAST when I took my foot off the brake that it was ALWAYS ready to go again by the time I could touch the accelerator.
The other thing I worried about was air conditioning. In Houston, we're used to features & whatnot conceived in more temperate places being absurdly poor fits for our summers, but BMW was smart enough to loop the climate control system into the start/stop loop. In the summer, at a long light, it would still kill the engine, but it would restart it if the cabin temp started rising, so that the compressor could run. In really hot weather, it didn't seem to engage at all.
My sense is that in a well-made car the level of additional wear and tear is pretty minimal. Our BMW was a lease so we don't have it anymore, but BMW warranties are such that I suspect they wouldn't ship that feature if it was going to produce a bunch more broken starters inside a normal 7-10 year range or whatever the "certified preowned" warranty window would be.
posted by uberchet at 6:55 AM on October 23, 2019 [2 favorites]
The seamlessness was really shocking. At first, I assumed it would impose a delay on getting going at red lights, but it restarted SO FAST when I took my foot off the brake that it was ALWAYS ready to go again by the time I could touch the accelerator.
The other thing I worried about was air conditioning. In Houston, we're used to features & whatnot conceived in more temperate places being absurdly poor fits for our summers, but BMW was smart enough to loop the climate control system into the start/stop loop. In the summer, at a long light, it would still kill the engine, but it would restart it if the cabin temp started rising, so that the compressor could run. In really hot weather, it didn't seem to engage at all.
My sense is that in a well-made car the level of additional wear and tear is pretty minimal. Our BMW was a lease so we don't have it anymore, but BMW warranties are such that I suspect they wouldn't ship that feature if it was going to produce a bunch more broken starters inside a normal 7-10 year range or whatever the "certified preowned" warranty window would be.
posted by uberchet at 6:55 AM on October 23, 2019 [2 favorites]
Response by poster: Yes I am in Houston. I did not think about the AC part of it. I failed to mention I had read about 3 types of this feature: traditional, tandem solenoid, and permanentaly engaged starter. The last one is supposedly the best. In any case, I was driving the new Outback.
It looks like the choices are to either learn to live with it or find a vehicle that does not have it. With the floods we have here, I probably should buy an old Army truck, lol.
posted by jtexman1 at 7:04 AM on October 23, 2019
It looks like the choices are to either learn to live with it or find a vehicle that does not have it. With the floods we have here, I probably should buy an old Army truck, lol.
posted by jtexman1 at 7:04 AM on October 23, 2019
Agree it is really common here in Europe - takes a minute to wonder why the engine has cut off, but you get used to it. AFAIK you can almost always turn it off if it gets on your nerves.
posted by sedimentary_deer at 7:23 AM on October 23, 2019 [1 favorite]
posted by sedimentary_deer at 7:23 AM on October 23, 2019 [1 favorite]
I recently picked up a 2010 Prius with 154,000 miles on it, and it shuts off while stopped. The specimen I bought had been maintained indifferently (and apparently cleaned never... eeeeww) but the stop/start works flawlessly.
I would not worry about the durability of this feature.
posted by workerant at 7:46 AM on October 23, 2019
I would not worry about the durability of this feature.
posted by workerant at 7:46 AM on October 23, 2019
Part of the development of this feature involves an upgrade to the starter motor hardware in order to deal with the increased demand, as well as other features that render it essentially transparent to the driver, including keeping heating and air conditioning running while the engine's off from the battery.
So, because I'm very noise sensitive and only drive average rental cars, I find myself irritated when the start-stop system's not warmed up, and the engine stays running at the lights. So I consider the lack of noise & vibration from the engine idling to be a big advantage, but you may be less sensitive to that or in a quieter car.
The fuel economy gains are in the region of 3-10%, depending how and where you drive, so it's also worthwhile from that point of view.
posted by ambrosen at 8:17 AM on October 23, 2019
So, because I'm very noise sensitive and only drive average rental cars, I find myself irritated when the start-stop system's not warmed up, and the engine stays running at the lights. So I consider the lack of noise & vibration from the engine idling to be a big advantage, but you may be less sensitive to that or in a quieter car.
The fuel economy gains are in the region of 3-10%, depending how and where you drive, so it's also worthwhile from that point of view.
posted by ambrosen at 8:17 AM on October 23, 2019
about how much more wear and tear this puts on the starter and battery over the normal life of a car?
As mentioned, not any more wear and tear than has been predicted and allowed for. Starters are beefier now, and charging systems robust enough that this is not even something I would think would be an issue beyond usual 'electrical system has an issue' randomness.
It looks like the choices are to either learn to live with it
There really is no 'learning to live with it past the first 20 mins of "What just happened....? Oh, it shut off'. If you lighten pressure on the brake the car will restart so if you have only just enough pressure to stop the car rolling you can get it to restart before you press the accelerator, for all the cars with this system I have driven. You can learn this pretty fast or just start rolling a touch early for those rare occasions you need instant power - to nip between traffic on a turn across a lane, for instance. But other than that, there are no issues with this.
posted by Brockles at 8:43 AM on October 23, 2019 [4 favorites]
As mentioned, not any more wear and tear than has been predicted and allowed for. Starters are beefier now, and charging systems robust enough that this is not even something I would think would be an issue beyond usual 'electrical system has an issue' randomness.
It looks like the choices are to either learn to live with it
There really is no 'learning to live with it past the first 20 mins of "What just happened....? Oh, it shut off'. If you lighten pressure on the brake the car will restart so if you have only just enough pressure to stop the car rolling you can get it to restart before you press the accelerator, for all the cars with this system I have driven. You can learn this pretty fast or just start rolling a touch early for those rare occasions you need instant power - to nip between traffic on a turn across a lane, for instance. But other than that, there are no issues with this.
posted by Brockles at 8:43 AM on October 23, 2019 [4 favorites]
I read somewhere years ago, that even if this technology caused the starter to wear out prematurely the savings on gas would pay for several new starter motors anyway. In practice the starter motors are just as reliable as older cars.
What I find is that if I do a lot of start-stop short journeys then the system is smart enough to automatically turn itself off so that the battery level doesn't get too low.
posted by Lanark at 12:07 PM on October 23, 2019
What I find is that if I do a lot of start-stop short journeys then the system is smart enough to automatically turn itself off so that the battery level doesn't get too low.
posted by Lanark at 12:07 PM on October 23, 2019
My hybrid with this feature was 14 years old with almost 150,000 miles when I traded it in, and it never had a problem with the starter.
posted by Dolley at 5:58 PM on October 23, 2019
posted by Dolley at 5:58 PM on October 23, 2019
Our Prius is ten years old and this system works flawlessly. Since the car is smart enough to manage its own power, if either the hybrid of 12V batteries are in danger of discharge, the gas engine automatically restarts (even at idle) to keep the charge up. Since the car doesn't need the gas engine to accelerate from a stop, engine starting from a red light has never been a concern.
The local transit system's newer 40-foot coaches use idle-stop systems as well. I understand they are also some form of hybrid, but at any rate I never detect any hesitation to start moving after the engine has shut down.
posted by lhauser at 7:35 PM on October 23, 2019
The local transit system's newer 40-foot coaches use idle-stop systems as well. I understand they are also some form of hybrid, but at any rate I never detect any hesitation to start moving after the engine has shut down.
posted by lhauser at 7:35 PM on October 23, 2019
Engineering Explained has a great video on start/stop systems. It turns out, it's more efficient to turn off the engine after ~7 seconds of idling, depending on displacement.
This focuses a lot more on the fuel efficiency gains, but he also touches on wear and tear caused by start/stop systems. His conclusion is, "don't worry about it, because the start/stop system uses a separate starter!" Jump to ~4:20 for his bit on wear and tear.
posted by spbb at 12:06 PM on October 24, 2019
This focuses a lot more on the fuel efficiency gains, but he also touches on wear and tear caused by start/stop systems. His conclusion is, "don't worry about it, because the start/stop system uses a separate starter!" Jump to ~4:20 for his bit on wear and tear.
posted by spbb at 12:06 PM on October 24, 2019
This thread is closed to new comments.
posted by Dolley at 5:50 AM on October 23, 2019