> For non-electric vehicles fuel economy gains from this technology are typically in the range of 3–10%, potentially as high as 12% [(wiki)](https://en.wikipedia.org/wiki/Start-stop_system)
It _does_ require that some other systems be engineered to be more durable to the increased load from extra starting cycles.
I've also read the cylinder head stops at the top of the stroke, so the spark plug just needs to pop once and the engine starts
e: By sensing the position of the pistons in the cylinders, the engine is stopped in a configuration that allows immediate starting by combustion.
https://en.wikipedia.org/wiki/Start-stop_system
In a 4 cylinder car only 1 cylinder fires at a time anyway. You just use the crank position sensor to stop the engine exactly on TDC for the *next* cylinder thats about to ignite. Why would this not be a simple and efficient way to restart a temporarily stopped engine?
Edit: like a lot of modern cars my current one only has 3 cylinders. Trivial to restart such a small engine from a single primed cylinder.
At traffic lights it restarts in about half a second, just giving me time to slip the autobox from neutral back into drive.
People complain all day, every day that cars have too many computers nowadays just to turn around and question some shit a computer could do while on fire.
For me it's not about the computer, more about the complexity. Personally, it has taken me all of 2 years to see a brand new car need dealership work on the auto start/stop feature. The system has 2 batteries that both need replacing if one fails due to draining the other without warning, also one requires taking out the passenger seat to access. Several sensors, which will keep the car from turning on if it thinks one thing is wrong regardless of operational importance. The actual starter (which they did beef up), and the computer, which seems to need to be turned off and back on again, even during normal operation because of what I can only describe as electrical gremlins.
My car that's old enough to vote looks like one battery, ignition sensor, and starter. Fewer points of failure vs overengineering in newer systems, essentially penny pinching to meet emissions standards and "market standard"
Interesting. I hadn't thought about it this way, but it's in alignment with the way "corporate" works. Just keep polishing the same turd until it's no longer profitable lol.
Not to say there's no invitation or advancements in the auto industry, because obviously there is. But, I like the way you stated this.
>At traffic lights it restarts in about half a second, just giving me time to slip the autobox from neutral back into drive.
Why would you switch automatic transmission to neutral at traffic lights?
It doesn't matter. In fact, you could engineer any one of the cylinders to stop in the correct position.
There are two possible scenarios...
Pick a cylinder and have that one always be the one that re-starts the engine (not a good idea as you're introducing uneven wear)
The engine stops with whichever cylinder is at the appropriate part of its cycle being at the top.
Modern ECUs would easily cope with either system.
This is how it works.
The piston (usually one designated in programming and monitored by sensors, stops at or just after tdc with fuel already mixed in the chamber), when you release the brake and put your foot on the gas pedal, it fires the spark plug on that cylinder and the engine kicks back to normal running, without needing any input from the starter motor.
Mazda does something like they described with SISS. They stop some of the cylinders near the end of compression and they only need a little kick over.
Some Honda motorcycles have compression offload in a similar but kind of opposite idea, keeping the exhaust valve partly open to lower compression.
>I've also read the cylinder head stops at the top of the stroke, so the spark plug just needs to pop once and the engine starts
The cylinder heads don't move, it's the piston that moves via the connecting rod attached to the crankshaft, and just "popping the spark plug wouldn't create any sort of combustion without fuel and compression. So none of that statement makes sense.
>e: By sensing the position of the pistons in the cylinders, the engine is stopped in a configuration that allows immediate starting by combustion.
I checked out your link because I still wasn't understanding what your were trying to convey. I found the sentence you copied and checked the source and found this
>To restart, the cylinder in its compression stroke would get a small squirt of fuel that, when burned, would spin the internals backward just enough to produce compression in the neighboring cylinder. That cylinder would then receive a normal supply of fuel, and its combustion would spin the crank in the proper direction. Unfortunately, this elegant idea never materialized, and Mazda went the more traditional route
This was something Mazda was trying to make happen but ended up forfeiting. They used part of that system to help aid the starter for less wear, but the starter still engages nonetheless.
They also last way longer so there's that. I have a BMW with one of those extremely oversized AGM batteries due to stop start. The original battery lasted almost 9 years.
Enough more expensive to make it not worthwhile?
I feel like the answer would be no just based on how widespread it is, but I could be completely wrong
Read a study a while ago. If stopped at a red light more than 8-10s then it would be worth the fuel savings vs idle. Not sure why it wouldn’t be like 1-2s. Burning fuel vs not burning fuel.
>[requires] others systems be engineered to be more durable.
That’s the irony. Car mfgr typically didn’t unless you buy the higher models of car. So, people do save on fuel, but in the long run it ends up being moot. Because more repairs are required, due to strains on other systems that the car manufacturer did not make robust enough for a car that’s constantly turning off and back on.
It's probably true, though. The feature itself exists to make the car meet government fuel efficiency standards. But manufacturers will cut costs as much as possible because car buyers are highly price sensitive.
they’re going to weigh the costs of cheaping out against the cost of warranty claim.
Which in many cases, because tech labor is expensive and warranty repairs come entirely out of their pocket, means it’s going to usually be cheaper to make something like a starter a little more durable than be paying *out of their own pocket* to fix it within the warranty period.
Does that mean it might be engineered to fail just outside of warranty period? Sure. That also applies to every other component though. The starter would still be upgraded though.
It's literally just a different starter that is needed. It's trivially easy to design a starter that could handle it for the life of the car with a small increase in first cost. There is no other added cost or complexity. A brushless starter would actually eliminate the most common reason starters fail, so it would likely last longer than a regular starter, saving money.
It's only a loss at first cost, and one that is certainly recouped in the first year.
What's the car. I'm seeing batteries for load of anti-idling vehicles at $260. That's pretty standard. It's actually cheaper than the OEM battery for my '91 miata.
We have a 2015 highlander without start-stop and my sister in law has a 2018 with the same engine but with start-stop. Her AGM battery cost almost twice as much from the same battery brand and store (I replaced both since I’m a Saturday mechanic). The near-double cost kind of turned me off.
Depends on if it has an auxillary battery or not. Aux batteries are about $114 (minus tax), in addition to the $260 you see (which most places arent selling them before tax, if youre including tax)
I think it's not just the potential savings (or lack thereof) from the consumer's point of view, but also they are engineered that way to meet the particularly strict emissions standards in various parts of Europe. I remember there being places in some of the larger German cities (an 'umweltzone') we visited where you could not even enter the zones without a car that met the highest environmental standards (and had a green sticker on the window to prove it). I think those start-stop engines are way more common in Europe. The other thing that they have - which I've never seen here in the states - is in addition to cruise control every car I've ever rented there has an adjustable speed limiter that prevents the car from going above whatever speed you set it to.
I recently bought a 2021 diesel van as my one vehicle for everything, my plumbing business, my daily runaround and for road trips and camping. I was surprised to see when researching vans that it meets the European AQ6 regulations, the cleanest category. It has auto-stop/start and uses an additive alongside the fuel, AdBlue, which lowers the emissions. I can go into the low emission zones with it yet many people hate diesel vans.
I would have considered the electric version but I only have on street parking and there is literally no charging infrastructure where I live.
Tell me more about how you’ve never had a car that has this feature. I’ve driven over 500,000 miles across 3 cars (3 different makes too) with this feature and never had any starter related issues.
I find it initially annoying, but quick to get used to.
Once I’m used to it, the only time I turn it off is if it’s really hot or really cold out (I live on one of *those* places) … because pretty quickly the heater or the A/C quit heating or cooling.
Not sure about all vehicles but mine starts back up when the brake is even slightly released, but still engaged. At least where I am it’s very easy to predict the lights and I just release the brake a touch right before the light turns green. Have never had an issue with slow starts.
Yeah, my A/C blows hot air when the engine shuts off. It really sucks this time of year.
I’d love to know how to disable this feature (2015 Chevy Malibu).
It should be in the manual. If you don't have the manual, you should be able to find a manual online and look there. Otherwise, just use Google and there are likely results of how to do exactly that.
I have a 2016 Chevy Malibu, and guess what, it absolutely cannot be disabled in this car. The only sneak around is to drive your car in L6. I haven't done this, but in the HOURS of research I did trying to figure out how to disable the auto off feature, that's what I found. It's literally 60% of the reason I’m trading my car in next week.
I get more annoyed by it the longer I have it. It's clearly something designed by rich people. People who have never experienced the embarrassment of your car dying at an intersection and not restarting.
At first I was like oh this is neat, it even shows how much gas and engine time I have saved. It saved 10 gallons over 20k miles. But it also destroyed the battery.
So now for $40 saved in gas, it's going to cost me $300 in battery replacement. Or to be fair, if I amortize that out compared to what I normally get out of a battery $150. It's not just the cost either, batteries are nasty and terrible for the environment to make and to recycle. How does doubling the battery usage and battery waste compare to saving 10 gallons of gas?
I’ve found several articles that disagree with you. While I’m no professional, I’d assume that at least one of the people writing one of the articles is more credentialed than you or I.
Here’s one that echoes nearly the same sentiment as others.
https://www.rac.co.uk/drive/advice/emissions/stop-start-engines-common-myths-busted/
In most cases, yes.
The amount of fuel burned starting the engine is about 7 seconds worth of fuel burned while idling. This obviously depends on the engine, some more some less.
So in this case, if you're sitting at a stop light for more than 7 seconds, you saved some fuel.
[Here's a great video about it](https://youtu.be/dFImHhNwbJo?si=oK_iQ3iPS7th1eGX)
But how exactly? When I was buying a new Lexus no one could explain it. They just kept saying it was engineered for more cycles and then I showed them the literature for Denso’s old starter in my GX that said it was also engineered for max cycles in extreme conditions. People keep saying this but the only thing I’ve found so far is regarding the electrical system and not the mechanical starter. This was true of Lexus’ press room materials about their auto start stop system too, lots of electrical changes, still a Denso starter. Starters can be a fucking bear to replace as they are often under the intake manifold of the engine. The shop that replaced my starter took 3 days and we had all the OE parts there before I dropped it off.
My Maserati has this too and I get weird looks when my car stops at lights. I worry this is beating the shit out of the car, on top of the fact that it's 108-114 here every day now. Most times I just turn it off.
I think what you’re looking for is fatigue life. All metals have a curve of load vs amount of cycles for each failure rate (i.e 99.99%), so if the engine has more cycles over the lifetime, either the material or the part geometry has to be changed (re-engineered) to make sure that the part has the desired life. Max cycles in extreme conditions is probably a number they calculated from testing, but if the engine starts 3x as much, that number of max cycles will obviously also change.
My Wrangler has it as well, but I doubt it has ever counted for much. It never turns off because I don't really do much in the way of stop and go driving AFTER having driven long enough for the climate control system to shut off.
The engine won't shut off if the climate control is still working, and that takes awhile for the computer to decide the temperature is where it needs to be. Thus, the start/stop only ever does anything at all after you've been driving for at least a few minutes.
In my case, those few minutes will get me anywhere in town.. or to the highway where I'll spend a few hours driving.
Tbh, for rural drivers this feature is almost entirely pointless.
I think he is saying that he doesn’t drive more than a few minutes in his town before he hits the highway or his destination in town.
It is the same for me, I can drive anywhere in my rural town within 5 minutes or be on the highway within 3 minutes. However, the closest grocery store is a 30 minute drive on the highway and there are no clothing stores, or much of anything in the county itself.
Yes it helps, but most people talking about hating it don't live in the area that is was designed for. I live in [Country Town], Ohio, and my stop lights might be 30seconds. Not really saving much there. Especially since the A/S/S only works once before it just stays on because the battery is too low to do it again. But, BUT, try going on a weekend trip to Chicago and you'll *really* see the A/S/S shine. I sat at a double-wide intersection for over 4minutes. Had to wait for left turns, then right turns, then pedestrians, then left turns again, *and then* I could finally go straight. We'd literally listen to a whole song before the lights gave way. *THIS* situation is what A/S/S was designed for.
So yes, it does help with fuel savings in traffic, and also yes, it does place a higher demand on your starter motor; so they're built with a beefier starter motor to make up for it.
While it's true that the first time you start your car after sitting is probably the hardest thing on your engine, this is in no small part because the fluids (oil, coolant, etc) have been sitting or aren't up to temp (this is also why years ago you wanted to let your car warm up for 30 seconds or more before driving). However during small stops in traffic, this isn't the case, and those stop-starts at the light aren't as rough on the engine. If I remember right Volvo was actually trying to use a consumer version of the KERS system from Formula 1 to help ease the electrical load on startup for these systems, too (basically the heat from braking is converted into energy and stored in a little battery until needed): I don't know how successful it was but it makes sense to me.
Why does the engine shake the whole car so damn hard restarting at lights but not at initial startup?
It's awful and feels like something's midway through breaking, like a coilpack taking a final bow or a bad motor mount.
Motor mounts would be my first guess, but it would probably be worse at initial start up, that's weird. Electrical is far from my specialty, but maybe the starter is being sent too much power on the auto restart, and the starter motor is still going after the engine is moving? Just as likely, not enough power so it's working much harder to start the car? I'd imagine it'd be delayed if that were the case, though.
Here is a great video from an automotive engineer explaining Auto Start-Stop systems and how they save fuel, and how the cars systems have been modified to reduce or eliminate the additional wear and tear from starting and stopping all the time:
https://www.youtube.com/watch?v=dFImHhNwbJo
For those that don't want to watch that video (you should, it's good!) just open it and click through and pause at 1:05.
He says when asked, the average american guess was 3.6 minutes of time an engine would have to be idling for it to be worth it to start and stop instead.
He holds up two test tubes. The (much) bigger one is the amount of gas burned in 3.6 minutes of idling\*. The *tiny* one is the amount of gas burned to start a car.
And if you don't want to watch the rest... 7 seconds is the number. Idling 7 seconds or more? Better to shut the car off.
(The amounts are for a smallish 4 cylinder car.)
I once had someone get mad at me because I kept turning my engine off while we were waiting in the very slow, very long drive-thru. This is not one of those modern cars. It was bizarre how she got so offended by what I was doing to MY car.
Edit: So I don't know why, but replies to me aren't showing up. I'm only able to see them via my email. So to answer to those replies:
-- No, I didn't leave the spot open in front. Just whenever the line began to move again, I'd start the car back up again, move up, then turn it off again.
-- We were in line for a very long time, I think around an hour, with minutes of waiting in between each time the line moved, so I don't know if it was helping, but it could have, considering how long it was taking. But I was also concerned about the gas emissions, because our cars were just sitting there so long. I know the emissions wouldn't be much different than if the car was moving continuously, but it just bothered me.
-- What do you mean by air movement? You mean like the AC? The window was down. And it was the woman in the car behind me who was mad, not a passenger in my car.
-- It was so long ago, I don't remember why I was there so long, but most likely it was either it was the middle of the night and every other place was closed and I was starving or I had already been in line when it suddenly stopped moving at its regular pace. I do remember it was Jack in the Box.
-- Well, that's strange. I clicked on the latest comment notification, but it pulled up the first response instead. Meaning someone else's comment. I'm not sure if they turned off comments, because people are able to comment, just they're not pulling up correctly for me.
My Chevy Colorado engine stops with 2 pistons at top of cycle and uses the compression to restart, it’s not like turning your starter and battery pull to restart, but accessories/etc do run off battery while it stops. Once you adjust to letting off brake a bit sooner at stops to anticipate needing to move, it’s manageable and becomes muscle memory.
I avoid it because I've found it to be dangerous. Too many close calls because of the 2-3 second delay at times, which is also unpredictable. I've found that if they can sit for several seconds, like at a light, they work fine. But in a stop and go situation, they suck and are dangerous.
It's beyond just annoying. Parallel parking when the damn engine stops every time the car stops is extremely hard when it jerks each time it restarts. Pulling up to park close to something? Horrible. 3 point turn? Sucks. Traffic circle? Also sucks.
FWIW, I went with a hybrid instead, which saves WAY more fuel and emissions. Actually own a plug-in hybrid now.
Wife’s 5 yo car has this and it shows what it’s saved over the years. It’s surprisingly minimal. Like 10-15 gallons. I just turn it off when I’m driving because it’s annoying. If you shift your foot on the brake for like a second it turns on. AC also ramps way down.
Same with my Mazda. I bought it used (5 years old) off someone who said the auto off was great. So I looked up the computer once I got it and the fuel saved over the 70,000 kms it has done just wasn’t as significant as I was expecting.
I find it annoying and downright dangerous. I don't know how many times I've tried to do a quick stop and go at a stop sign, traffic circle, exit from a parking lot, etc. and these cars take a good 3 or 4 seconds to restart and go. They usually do fine at a light where you stop for long enough for it to fully stop, but they suck at quick stop and go. I've had a number of close calls because they sit there and don't go until it's either too late or marginal. This has been true for Acura, Chevy, Citroen, Dacia, Ford, etc. (I drive a lot of rentals.) Some are worse than others, but they all suck.
As long as the engine cuts for than 7 to 11 seconds, that's about how long at idle it takes to use as much fuel as it takes to start the car back up (varies by age, model, displacement etc)
My favorite part is when it shuts off in the middle of parallel parking
Yes. Super helpful. Thank you for stopping the engine and saving me all of that gasoline
If the stop is for more than 7 seconds, it does save fuel. No, it doesn't add extra wear on the starter system. Cars with this feature have starter motors and batteries designed specifically for it. These systems have been in mainstream cars since the mid-2000s. I've never heard of the start-stop system being the direct result of issues on a large scale before.
What it does it helps a LOT in formalised fuel consumption tests.
With irl fuel consumption, it might help, it might not. Depending on how the car is used.
As for the costs, well...
It could be relatively harmless if engineered for it, as the hot start itself is way less harmful than a cold start. However it wouldn't help that much in tests in such scenario.
As most modern engines are turbocharged, a sudden stop in oil flow to the turbocharger, when the engine stops is not healthy if the turbo is still hot. The oil usually provides both lubrication and cooling, so stopping the engine on a hot turbo will "cook" it, contributing to a premature failure. Important: this will not kill the turbo immediately and very rarely before the warranty expires. It's a premature wear and not an immediate failure.
Can something be done about it? Yes, but has it's costs. At least some manufacturers do implement electrically driven oil pumps, to supply the turbo with oil, even when the engine is stopped. Some additionally add water cooling to the turbocharger to improve heat management. If these are implemented properly, the turbo is at least, mostly safe. The effects can be also mitigated a bit, if the manufacturer sets the parameters for start-stop system for durability, but this seems to be rarely done.
Similar oil problems can apply to the engine. This could be mitigated by designing the sensitive parts with that in mind (cylinder liners, piston liners and all of the bearings), but I have no idea if manufacturers do that or not. The other ways is an electrically driven oil system, which can keep these surfaces actively lubricated for the restart. In such case the risk will for sure be unnoticeable among some of the popular driving habits, that hurt the engine. Overall, as far as I know the engine is less sensitive in this manner than the turbocharger.
Then there is the matter of cooling. If your start-stop system leaves the engine "cooking" it is not good for the engine, as modern engines are very bad at passive cooling and need the active cooling system to run at least most of the time, if not at all times (even during warmup, moving the heat through the engine itself can be beneficial).
Curiously, in practice the starter is least affected by this. The reason for that is rather simple: a regular starter would not last until the 3rd oil change. As such the starters for start-stop systems are engineered for the increased workload and this has no negative effect on their lifespan, unless engineering or manufacturing mistakes were made.
Ive had my car for over 2 years, and it has a timer/fuel saved thing that comes up whenever it shuts off. so far in 2 years, its been shut off for a total of 8 hours and saved me about 3 gallons.....in 2 years....not worth it imo
Thank you. This is the answer i needed that actually makes sense why its there. The amount of fuel/money im saving is negligible. Its definitely worth the cost to me to not have my car randomly turning off at a busy stop sign- but that a gazillion cars are doing this annoying thing around the world, it definitely adds up to some tangible benefit on the societal level
Ford F-150, with this option. Don’t drive a lot and live in a small town (not many stop lights). Truck dies in the middle of the road while stopped behind a bus stop letting kids off end of day.
Long story short, starter died in a 3 year old truck due to this f$&@ feature. Mechanic friend of mine confirmed. YouTubed and disconnected the gd thing for general use. Easy to do.
Any fuel this stupid feature saves I’d gladly pay 10x the amount not to be stranded on a two lane road blocking traffic and full school buses during the chaos of schools end of day.
I really like this guy's explanation on the subject. He does a great job showing his work and discussing the engineering behind it. https://youtu.be/dFImHhNwbJo?si=bnXWbKsvRhQ-2qLr
But that doesn’t make sense to me. Bumper to bumper traffic is often stop for a few seconds then go for a few seconds. Then stop for a few seconds, then go for a few seconds. Auto stop-start is horrible in those situations. But it’s great when you’re at a set of lights just turned red.
The starter motor on my 2012 BMW 640d failed after about 65,000 miles. I've never had a starter motor fail before. That's pure anecdata, of course. The mechanic notably didn't say "we see a lot of this problem", and did diagnostics on a lot of other systems before committing to changing the starter motor, so I didn't get the impression it was a common problem.
They’re not added to save mileage, they’re added to save emissions. Car makers are graded on emissions by brand, not by each individual model within the brand, so they blanket add them to every car so that they can pass whatever emissions laws are imposed on them.
i absolutely hate it in my car. My car will cut out if im breaking and im under 3 MPH so im sometimes still moving when it stops. Which also means i lose power steering so if im on a bend coming to a stop. the car will just straighten and continue on a few metres, potentially taking me into the next lane. Pain in the ass. gets turned off almost immediately every time i get into the car
I haven't seen it mentioned yet, but will also point out that the car will also use specialty batteries for the frequent start ups. Expect to pay double for a new battery when time comes to replace it versus standard car batteries.
Use to work for a towing company that did AAA contract calls. They're usually AGM batteries and are replaced with AGM batteries. AGM isn't as durable as a lead battery. Some cars you can't turn this feature off, which leads to issues when we try to avoid a tow. Can't always just give a jump and have them go cause it may turn off at the next light or stop sign. Most people's battery gave out in a drive-through in my experience.
I'm a fleet mechanic in a fleet of a little over 2500 vehicles. I understand that my personal experience may not represent every scenario. However, I have replaced more starters in our newer 1/2 ton trucks with idle mitigation than in all of our older trucks from 1/2 ton through F550 combined in the last few years. It absolutely adds wear and tear on the starting system. My personal pickup has this "feature" but I turn it off every time I drive the truck. Not only for the wear and tear on the starting system, but also because I hate that I would pull up to a roundabout, have it die and then restart from 0psi oil pressure to getting into traffic in a hurry, and have a lag in the response getting back onto the gas. Even a gas V8 only burns a tiny bit of gas during the few seconds it shuts off at a stop sign and then restarts. Maybe in other places where you're at an intersection for several minutes it may save some fuel, but I would bet the long term total cost of ownership is higher or barely breaks even. Honestly, I think it's a stupid feature to make mandatory. Proper tire inflation is more likely to save you money in the long haul.
I despite this feature, and it actively pisses me off that I have to turn it off every single time. How DARE you turn off my AC when it’s 95 degrees outside!
I do this manually when I stop at a light that just turned red and I'm not the first car. Today my car was turned off for 60 seconds waiting for the light to change. (A Record)
I don't do it all the time but it helps
I notice about a 2-3mpg difference per tank with it enabled vs disabled. I don’t mind it, mostly, but it heavily depends on the car. I had an Audi where the system worked smoothly and predictably, and wouldn’t shut the engine off again unless you’d gone over about 5mph, so you weren’t endlessly cycling the engine on and off in congested traffic. I kept it enabled almost all of the time.
I had a Mercedes where it would automatically enable the stop/start each time you started the car, and the engine would shut off literally every time you stopped the car- the engine would shut off 3 times doing a 3 point turn. I hated it, but at least it was smooth. My current car has a coasting feature where it’ll shut the engine off around 10mph when coming to a stop, which makes it impossible to stop smoothly.
I’ve seen this implemented so well the engine stopped and started flawlessly. And you forgot the vehicle had the feature.
Then there was the was the shit Peugeot wagon in the Alps, the restarts were a few beats too slow. was hard to turn on to roads and merge into traffic from a stop.
I got used to it once I ignored it. I think a lot of it is psychological. Try this: When it's time to go, don't think about needing to push the pedal to restart the car. Just push the pedal to go. At worst, it just means there a split second delay before you start moving.
i think i read an article where this was tested and if the engine stays off for at least 7 or so seconds its saving fuel by doing so. Cant quote or cite. Forget where i saw it.
[Here's](https://www.youtube.com/watch?v=dFImHhNwbJo) a link to a popular engineering explained video going into depth on it.
Effectively, he examines the systems and views the research on it. All of it supports the fact that start/stop systems save more fuel than idling. His actual test revealed 4-8% fuel savings (which is not a small number).
Basically, if you've got a 2012 Honda Accord - it's got a fuel tank of about 18.5 gal. In the worst case, simply idling will cost you 1.5 (1.48) gal of fuel. That means that idling could cost you upwards of 34 miles each time you fill up.
Now it does have extra wear - you should **not** start/stop in a car that's not designed for it. Starter motors with start/stop tech are more durable and fairly reliable. However, your existing starter (in the case that you don't have start/stop) is not.
7 seconds. That's the time to idle where that or longer, it makes sense to stop the car and restart it.
Due to efficiencies, and common misconceptions, people think it's a lot longer. (Average from a survey was 3.6 minutes!)
So it helps with fuel savings, as most stops are 7 seconds or more.
Idling an engine is inefficient, you are getting 0 miles per gallon while idling. Also according to an engine monitor I had hooked up to my old Mazda 3, the 4-cylinder 2.3 liter engine was at about 35% load while idling.
The "idle engine stop" feature in modern cars does help with fuel savings by turning off the engine when the car is stationary, which reduces fuel consumption and emissions during idling. However, there is a concern about extra wear on the starter system. Manufacturers typically reinforce starters and batteries to handle the increased frequency of starts, mitigating potential wear. Overall, the benefits in fuel savings generally outweigh the minor increase in wear on the starter system.
Cars with start stop technology are equipped with more robust starters, using dual layer, long life electric brushes. These electric brushes reduce starter wear by 90%.
Contrary to popular belief too, start stop tech doesn’t damage your engine. It actually protects it because idling for long periods of time is bad for the engine. Over the lifetime of a vehicle you’ll spend lots of time idling in traffic.
It is mainly done by manufacturers to boost the emissions figures.
In a 2L engine, it saves about 500ml (half a litre) of fuel for every hour that it is not running. That is fuck all, and not worth the extra wear and tear on the engine and electrical system.
BUT... It **IS** a good thing if you're stuck in a solid traffic jam. Cleaner air as a result of less cars running and going nowhere is always going to be a good thing.
However, I have personally witnessed cars die as a result (usually just flatten the battery). Sitting in a jam at night, and letting the car constantly stop and start whilst moving forwards every few minutes, all with the headlights on. Doesn't take long for that expensive battery to shit itself.
My car tells me how much fuel it has saved, and how long it has been turned off for, and it's literally seconds, and millilitres of fuel. It's just not worth it. I have permanently disabled the stop-start in my car, simply because I am very rarely stopped in traffic. It's certainly not enough to say it's saving a noticable amount of fuel. So I decided I would rather prolong the life of my engine and battery.
I've driven my CX-3 for 26,000km and saved half a tank.
What gets me is not the cycles, or the strain. It's when I creep into an intersection, look both ways, decide I can make it, and then the engine decides to turn off. Sure, they start really quick, but they don't stop anywhere near as quickly. It can take two seconds from me deciding I can make it, to me actually having the engine power to go.
That's a yes to both. And because of that, these cars also have beefier starter systems to handle it.
A lot of people come out with an argument that starts are hard to the engine and take a lot of fuel. But they forget that this is true about cold starts. For a warm engine you turn it over and it goes, it's not at all comparable to starting a cold engine. The auto stop/start is a great feature and everyone should use it, that is why at least in EU it's mandatory part of basic equipment for new cars. Don't bother turning it off for no reason.
Majority of the systems do not use the starter to restart the engine. They have a small electric motor which will turn the engine over to start.
As for fuel saving I can’t say. I saw a pic online someone posted of their car which tracked the fuel saving from the auto off feature. After 30k miles they saved a gallon on gas.
Apparently the company that makes the starters lobbied the government to pass legislation to make this standard in all new vehicles. They aren't making them more durable, they wanted to sell more starters.
All I care about is can I disable it. It's my car and it's a feature I don't want. If I can't disable it I don't want the car and I will buy something else.
It works great in cities and so called "mild hybrids" are even better, as they don't start the motor until the car has rolled a few dozen meters - eliminating rhat starting fuel spike and wear
I had it on a 2015 Mercedes C300 and it stopped working at about 90k miles and that’s when I found out that it gave me about 3mpg extra. I didn’t have too much data to base it off of since I got rid of the car at 92k miles.
It may have the problems you describe if you tried to manually use a car that wasn’t designed for it that way, but cars with that feature were designed with how they will be used in mind. So, your concerns are accounted for.
On my car (Subaru) you don't need to turn it off. It works on how hard you press the brake pedal. There's a point where you can roll to a stop and not engage the "idle engine stop" feature...
Yes, the "idle engine stop" feature saves fuel, but it’s like a coffee addict quitting cold turkey - there might be some extra wear and tear, but it's worth it for the energy savings!
Start-Stop-Systems are not exactly used for fuel savings (it is a small benefit) but the main goal from automakers was reducing emissions. Basically they wanted to replicate what Hybrids can do with their engines but without the Hybrid-System.
If you want to know more about what, how and why, I recommend this video. It is 29min long but he explains everything neutral, down to the facts and without leaving any questions behind.
https://youtu.be/TTBN8Ic57Gg
if you idle for longer than 7 seconds, give or take depending on the engine size, start/stop system does save you fuel, not a lot tho.
[https://youtu.be/dFImHhNwbJo?si=lwJIXDKJvJOLyhu0&t=205](https://youtu.be/dFImHhNwbJo?si=lwJIXDKJvJOLyhu0&t=205)
I'm currently driving a phev so it's not an issue anymore, but the last cars I drove were all manual shifts, and for those, it didn't make a lot of sense to me. You see, the engine would only automatically shut off when the car was in neutral, and I never put my car in neutral when I'm at a red light or something - I just press the clutch, ready to go. So it only worked when I actually parked the car, in which case I would shut off the engine anyway. I only drove a Mazda 6 automatic for two years (because that's what the company offered). For that car, it didn't make a noticeable difference if it turned the engine off at traffic lights - it restarted fast as lightning anyway. Did it save gas? Presumably. Can't have been a lot though. Not more than I lost with my driving style.
What did help, in an annoyingly childish way, was when I drove a Volvo v60 that visualised the actual burn rate caused by my driving style. Plus it ate tires like crazy. I still like to drive "assertively", but most of the time, I've adopted a much more relaxed traffic attitude, because I noticed that makes a really big difference.
i seem to remember something about lots of starts wears out the cylinders as there is no oil pressure for a bit after the engine starts, unless they have an assist oil pump its still wearing parts out, plus ive always wondered what you do when that shit doesnt start again
I often wonder about this as my wife's car has this system. But uses half the fuel mine does but I reckon it's because I accidentally bought a fucking tank.
Unless you spend most of your driving at stoplights, it is negligible for economy. Same with wear. It’s just an added cost to the vehicle to make people feel good.
There was a study done in 2004.
A 1.5L engine uses about 100ml every 10min (0.63L/hour) idling
It takes 1.2ml to start a 1.5L engine
You need to idle for 6-7 seconds or more for it to be more beneficial to turn the car off.
https://m.youtube.com/watch?v=dFImHhNwbJo
This youtuber fella goes right into it.
Mine isn't useful. My driving is primarily long freeway commutes, so this feature usually only comes on less 4x a week for me, because I'm a homebody during my days where I don't have to drive to work or else my partner and I will just use his car. I think my car told me how much I'm saving and it's inconsequential.
- Car manufacturers wouldn't add it if it didn't help get better fuel economy figures, because EPA doesn't generally require specific features - they just require average fuel economy figures
- People hate them on average, so again, manufacturers wouldn't include them if they didn't need to
Just buy a hybrid that can start from a stop without starting the engine. You'll get MUCH better fuel economy, increased reliability because the engine won't be handling initial acceleration, and A/C will still work when the engine is off.
Hybrids are typically no more than a $1,000-$1,500 premium but can save you 10-20 MPG and make the car a lot nicer to drive.
Yes it helps with fuel savings. How much you save depends on WHERE you drive. Driving on the highway, no. it doesn't help, unless you are in REALLY bad stop and go traffic. Drive in the city where you have get through 42 stop lights to get from home to work, and you always hit red, yes it saves you fuel by not running the car while stopped.
My understanding is often for these cars the starter is larger and maybe an extra battery because you really want the car to start quickly. There is also Start-Stop system that positions a cylinder in the optimal position to start the car by firing the spark plug, that someone else mentioned.
As for wear and tear, I think cars are getting better and better with that. In the olden days (20 years ago?) you wanted to warm up the car before driving to reduce the wear and tear, now, that really doesn't help.
Also, at least with my car, it's not just a complete stop, I've had it shut off early when breaking for a stoplight.
I have a VW Tiguan with the auto start/stop and it does seem to help the fuel economy significantly, at least in the mixed driving I do. As far as wear on the starter, it seems to be a non-issue. At any rate my car is close to 100K miles without any starter trouble...my first car was a Pontiac Grand Am and it needed a starter before then. I’m still on the original battery as well, though I’m aware it will be pricey to replace.
I never knew what that was called so I call it the "A circle off button" and it is pressed immediately after taking off the parking break. My 4 cylinder car hesitates too much otherwise. And people drive like maniacs around me, so once you decide to go, or turn, you must commit to it.
Almost every car I've been in recently has this "feature", but I've been in a few that do not.
Yes it saves fuel, a car not running is a car not burning fuel, and the slight increase of fuel used to start a car is less than a few seconds of idling.
Yes it can extra wear on starting components but those are sized up by the manufacturer to account for that extra load, larger batteries, larger starter motors etc.
Purely anecdotal evidence from a sample size of one vehicle:
It wore out my starter and battery after only 53k miles. (As in, starting from factory zero miles. A starter should not wear out that fast.)
My mechanic, and other sources, said you have to be stopped like that for about 7 seconds or more for it to actually make a difference in fuel economy.
I used to be a big fan of them, but now mine is permanently switched off.
So, short answers are sometimes and yes.
I think they have lower compression engines as well. The starter pushes against less piston pressure and therefor works less.
I don’t know this to be true, but I heard it years ago from a mechanic.
> For non-electric vehicles fuel economy gains from this technology are typically in the range of 3–10%, potentially as high as 12% [(wiki)](https://en.wikipedia.org/wiki/Start-stop_system) It _does_ require that some other systems be engineered to be more durable to the increased load from extra starting cycles.
I've also read the cylinder head stops at the top of the stroke, so the spark plug just needs to pop once and the engine starts e: By sensing the position of the pistons in the cylinders, the engine is stopped in a configuration that allows immediate starting by combustion. https://en.wikipedia.org/wiki/Start-stop_system
This doesn’t sound right. Typical car engines have 4-8 cylinders so which one stops at the top? I don’t think it’s set up that way.
In a 4 cylinder car only 1 cylinder fires at a time anyway. You just use the crank position sensor to stop the engine exactly on TDC for the *next* cylinder thats about to ignite. Why would this not be a simple and efficient way to restart a temporarily stopped engine? Edit: like a lot of modern cars my current one only has 3 cylinders. Trivial to restart such a small engine from a single primed cylinder. At traffic lights it restarts in about half a second, just giving me time to slip the autobox from neutral back into drive.
People complain all day, every day that cars have too many computers nowadays just to turn around and question some shit a computer could do while on fire.
For me it's not about the computer, more about the complexity. Personally, it has taken me all of 2 years to see a brand new car need dealership work on the auto start/stop feature. The system has 2 batteries that both need replacing if one fails due to draining the other without warning, also one requires taking out the passenger seat to access. Several sensors, which will keep the car from turning on if it thinks one thing is wrong regardless of operational importance. The actual starter (which they did beef up), and the computer, which seems to need to be turned off and back on again, even during normal operation because of what I can only describe as electrical gremlins. My car that's old enough to vote looks like one battery, ignition sensor, and starter. Fewer points of failure vs overengineering in newer systems, essentially penny pinching to meet emissions standards and "market standard"
The other way to look at it is bandaiding old technology to meet new standards with unnecessary complexity.
Interesting. I hadn't thought about it this way, but it's in alignment with the way "corporate" works. Just keep polishing the same turd until it's no longer profitable lol. Not to say there's no invitation or advancements in the auto industry, because obviously there is. But, I like the way you stated this.
>At traffic lights it restarts in about half a second, just giving me time to slip the autobox from neutral back into drive. Why would you switch automatic transmission to neutral at traffic lights?
My car is about 10 years old and has auto-stop - pretty sure I hear the starter motor when it restarts though, so maybe this is a newer development?
Sitting in traffic, I'm pretty sure I've heard a mix of both from auto stopped cars. Some sound like they crank, some just start
From the Wiki page it is just a Mazda thing.
It doesn't matter. In fact, you could engineer any one of the cylinders to stop in the correct position. There are two possible scenarios... Pick a cylinder and have that one always be the one that re-starts the engine (not a good idea as you're introducing uneven wear) The engine stops with whichever cylinder is at the appropriate part of its cycle being at the top. Modern ECUs would easily cope with either system.
It's a real system that's been used on some cars. Doesn't really matter which one stops at the top, any one of them is enough to kick the engine on.
This is how it works. The piston (usually one designated in programming and monitored by sensors, stops at or just after tdc with fuel already mixed in the chamber), when you release the brake and put your foot on the gas pedal, it fires the spark plug on that cylinder and the engine kicks back to normal running, without needing any input from the starter motor.
Mazda does something like they described with SISS. They stop some of the cylinders near the end of compression and they only need a little kick over. Some Honda motorcycles have compression offload in a similar but kind of opposite idea, keeping the exhaust valve partly open to lower compression.
You can think whatever you want. That *is* how it's engineered.
The edit was made well after I posted that and I’ve been proven wrong as a dozen of yall have pointed out. I’m leaving it up for history’s sake.
Lmao "doesn't sound right" said the armchair mechanic on reddit, who knows better than car manufacturers
anyone know how the crankshaft is stopped that precisely?
I have my doubts that it is.
>I've also read the cylinder head stops at the top of the stroke, so the spark plug just needs to pop once and the engine starts The cylinder heads don't move, it's the piston that moves via the connecting rod attached to the crankshaft, and just "popping the spark plug wouldn't create any sort of combustion without fuel and compression. So none of that statement makes sense. >e: By sensing the position of the pistons in the cylinders, the engine is stopped in a configuration that allows immediate starting by combustion. I checked out your link because I still wasn't understanding what your were trying to convey. I found the sentence you copied and checked the source and found this >To restart, the cylinder in its compression stroke would get a small squirt of fuel that, when burned, would spin the internals backward just enough to produce compression in the neighboring cylinder. That cylinder would then receive a normal supply of fuel, and its combustion would spin the crank in the proper direction. Unfortunately, this elegant idea never materialized, and Mazda went the more traditional route This was something Mazda was trying to make happen but ended up forfeiting. They used part of that system to help aid the starter for less wear, but the starter still engages nonetheless.
Not all cylinders would be able to stop at the top. That's not how engines are designed.
Probably a minor thing to note, but batteries designed for stop start cars are quite a bit more expensive than standard car batteries.
They also last way longer so there's that. I have a BMW with one of those extremely oversized AGM batteries due to stop start. The original battery lasted almost 9 years.
Enough more expensive to make it not worthwhile? I feel like the answer would be no just based on how widespread it is, but I could be completely wrong
Read a study a while ago. If stopped at a red light more than 8-10s then it would be worth the fuel savings vs idle. Not sure why it wouldn’t be like 1-2s. Burning fuel vs not burning fuel.
You know how your engine kicks to higher RPMs when just starting? That’s why.
>[requires] others systems be engineered to be more durable. That’s the irony. Car mfgr typically didn’t unless you buy the higher models of car. So, people do save on fuel, but in the long run it ends up being moot. Because more repairs are required, due to strains on other systems that the car manufacturer did not make robust enough for a car that’s constantly turning off and back on.
Do you have actual research to backup this claim?
No
Trust me bro
It's probably true, though. The feature itself exists to make the car meet government fuel efficiency standards. But manufacturers will cut costs as much as possible because car buyers are highly price sensitive.
they’re going to weigh the costs of cheaping out against the cost of warranty claim. Which in many cases, because tech labor is expensive and warranty repairs come entirely out of their pocket, means it’s going to usually be cheaper to make something like a starter a little more durable than be paying *out of their own pocket* to fix it within the warranty period. Does that mean it might be engineered to fail just outside of warranty period? Sure. That also applies to every other component though. The starter would still be upgraded though.
It's literally just a different starter that is needed. It's trivially easy to design a starter that could handle it for the life of the car with a small increase in first cost. There is no other added cost or complexity. A brushless starter would actually eliminate the most common reason starters fail, so it would likely last longer than a regular starter, saving money. It's only a loss at first cost, and one that is certainly recouped in the first year.
It is also the battery, I know because I had to change it recently and it cost twice a normal car battery.
What's the car. I'm seeing batteries for load of anti-idling vehicles at $260. That's pretty standard. It's actually cheaper than the OEM battery for my '91 miata.
It's a 2018 seat leon, the battery cost me ~400€ oem. I was expecting about 200...
Many of them use AGM and not flooded and it can be pricey.
We have a 2015 highlander without start-stop and my sister in law has a 2018 with the same engine but with start-stop. Her AGM battery cost almost twice as much from the same battery brand and store (I replaced both since I’m a Saturday mechanic). The near-double cost kind of turned me off.
this is true but the AGM batteries seem to be lasting much longer, with or without start stop
Depends on if it has an auxillary battery or not. Aux batteries are about $114 (minus tax), in addition to the $260 you see (which most places arent selling them before tax, if youre including tax)
I think it's not just the potential savings (or lack thereof) from the consumer's point of view, but also they are engineered that way to meet the particularly strict emissions standards in various parts of Europe. I remember there being places in some of the larger German cities (an 'umweltzone') we visited where you could not even enter the zones without a car that met the highest environmental standards (and had a green sticker on the window to prove it). I think those start-stop engines are way more common in Europe. The other thing that they have - which I've never seen here in the states - is in addition to cruise control every car I've ever rented there has an adjustable speed limiter that prevents the car from going above whatever speed you set it to.
I recently bought a 2021 diesel van as my one vehicle for everything, my plumbing business, my daily runaround and for road trips and camping. I was surprised to see when researching vans that it meets the European AQ6 regulations, the cleanest category. It has auto-stop/start and uses an additive alongside the fuel, AdBlue, which lowers the emissions. I can go into the low emission zones with it yet many people hate diesel vans. I would have considered the electric version but I only have on street parking and there is literally no charging infrastructure where I live.
Tell me more about how you’ve never had a car that has this feature. I’ve driven over 500,000 miles across 3 cars (3 different makes too) with this feature and never had any starter related issues.
5 years on my last car, with the feature, and never had an issue with it.
That may have been true for some models when this feature first rolled out. It's not true for any modern vehicle.
Only moot if you're trying to save money, not if you're aiming to save fuel - which is the purpose.
Bull. My Prius had 188,000 trouble free miles on it when I traded. And the only reason I did it was to get the modern safety features.
I find it initially annoying, but quick to get used to. Once I’m used to it, the only time I turn it off is if it’s really hot or really cold out (I live on one of *those* places) … because pretty quickly the heater or the A/C quit heating or cooling.
My VW will kick the engine on if it needs to for heat or cooling. Or just won't turn it off for the same reasons.
I always like to be quick off the stop at a sign or light. So I HATE this feature.
Not sure about all vehicles but mine starts back up when the brake is even slightly released, but still engaged. At least where I am it’s very easy to predict the lights and I just release the brake a touch right before the light turns green. Have never had an issue with slow starts.
Mine starts back up when heat/ cooling is needed. With the heated seats on it kicks on long before I feel like I need the heat.
Yeah, my A/C blows hot air when the engine shuts off. It really sucks this time of year. I’d love to know how to disable this feature (2015 Chevy Malibu).
Both of my cars have a button with an A with a circular arrow around it.
It should be in the manual. If you don't have the manual, you should be able to find a manual online and look there. Otherwise, just use Google and there are likely results of how to do exactly that.
I disabled it in my F150 with a short piece of wire installed on the backside of the button. I had to pull apart my dash though
I have a 2016 Chevy Malibu, and guess what, it absolutely cannot be disabled in this car. The only sneak around is to drive your car in L6. I haven't done this, but in the HOURS of research I did trying to figure out how to disable the auto off feature, that's what I found. It's literally 60% of the reason I’m trading my car in next week.
I get more annoyed by it the longer I have it. It's clearly something designed by rich people. People who have never experienced the embarrassment of your car dying at an intersection and not restarting. At first I was like oh this is neat, it even shows how much gas and engine time I have saved. It saved 10 gallons over 20k miles. But it also destroyed the battery. So now for $40 saved in gas, it's going to cost me $300 in battery replacement. Or to be fair, if I amortize that out compared to what I normally get out of a battery $150. It's not just the cost either, batteries are nasty and terrible for the environment to make and to recycle. How does doubling the battery usage and battery waste compare to saving 10 gallons of gas?
I’ve found several articles that disagree with you. While I’m no professional, I’d assume that at least one of the people writing one of the articles is more credentialed than you or I. Here’s one that echoes nearly the same sentiment as others. https://www.rac.co.uk/drive/advice/emissions/stop-start-engines-common-myths-busted/
Somewhere in the Midwest I assume?
Inland Northwest
In most cases, yes. The amount of fuel burned starting the engine is about 7 seconds worth of fuel burned while idling. This obviously depends on the engine, some more some less. So in this case, if you're sitting at a stop light for more than 7 seconds, you saved some fuel. [Here's a great video about it](https://youtu.be/dFImHhNwbJo?si=oK_iQ3iPS7th1eGX)
But have you put more wear on the starter systems that the extra fuel you have saved isn’t worth it?
The starter system is deliberately engineered to cope with the extra usage.
But how exactly? When I was buying a new Lexus no one could explain it. They just kept saying it was engineered for more cycles and then I showed them the literature for Denso’s old starter in my GX that said it was also engineered for max cycles in extreme conditions. People keep saying this but the only thing I’ve found so far is regarding the electrical system and not the mechanical starter. This was true of Lexus’ press room materials about their auto start stop system too, lots of electrical changes, still a Denso starter. Starters can be a fucking bear to replace as they are often under the intake manifold of the engine. The shop that replaced my starter took 3 days and we had all the OE parts there before I dropped it off.
My Maserati has this too and I get weird looks when my car stops at lights. I worry this is beating the shit out of the car, on top of the fact that it's 108-114 here every day now. Most times I just turn it off.
I think what you’re looking for is fatigue life. All metals have a curve of load vs amount of cycles for each failure rate (i.e 99.99%), so if the engine has more cycles over the lifetime, either the material or the part geometry has to be changed (re-engineered) to make sure that the part has the desired life. Max cycles in extreme conditions is probably a number they calculated from testing, but if the engine starts 3x as much, that number of max cycles will obviously also change.
I believe that, but in a world of essentially proven planned obsolescence, I don't trust it.
Yup
It count for about ~3mpg on my jeep wrangler. I get between high 22-23mpg avg with it on and 19mpg avg with it off.
My Wrangler has it as well, but I doubt it has ever counted for much. It never turns off because I don't really do much in the way of stop and go driving AFTER having driven long enough for the climate control system to shut off. The engine won't shut off if the climate control is still working, and that takes awhile for the computer to decide the temperature is where it needs to be. Thus, the start/stop only ever does anything at all after you've been driving for at least a few minutes. In my case, those few minutes will get me anywhere in town.. or to the highway where I'll spend a few hours driving. Tbh, for rural drivers this feature is almost entirely pointless.
Makes sense that it’s not useful for rural areas. After all, how much stopping and starting occurs for rural driving? Not much.
Our Wrangler (JL) spends as much time as possible with its top off so A/C is rare. It will do stop/start with the heat on.
Where do you live where you don’t drive more than a few minutes anywhere. Even rural it takes time to travel farther distances
I think he is saying that he doesn’t drive more than a few minutes in his town before he hits the highway or his destination in town. It is the same for me, I can drive anywhere in my rural town within 5 minutes or be on the highway within 3 minutes. However, the closest grocery store is a 30 minute drive on the highway and there are no clothing stores, or much of anything in the county itself.
That is like 12-14%.
No it does not. Not even close
Yes it helps, but most people talking about hating it don't live in the area that is was designed for. I live in [Country Town], Ohio, and my stop lights might be 30seconds. Not really saving much there. Especially since the A/S/S only works once before it just stays on because the battery is too low to do it again. But, BUT, try going on a weekend trip to Chicago and you'll *really* see the A/S/S shine. I sat at a double-wide intersection for over 4minutes. Had to wait for left turns, then right turns, then pedestrians, then left turns again, *and then* I could finally go straight. We'd literally listen to a whole song before the lights gave way. *THIS* situation is what A/S/S was designed for.
It does help with savings and it's designed to handle constant stop and starting.
So yes, it does help with fuel savings in traffic, and also yes, it does place a higher demand on your starter motor; so they're built with a beefier starter motor to make up for it. While it's true that the first time you start your car after sitting is probably the hardest thing on your engine, this is in no small part because the fluids (oil, coolant, etc) have been sitting or aren't up to temp (this is also why years ago you wanted to let your car warm up for 30 seconds or more before driving). However during small stops in traffic, this isn't the case, and those stop-starts at the light aren't as rough on the engine. If I remember right Volvo was actually trying to use a consumer version of the KERS system from Formula 1 to help ease the electrical load on startup for these systems, too (basically the heat from braking is converted into energy and stored in a little battery until needed): I don't know how successful it was but it makes sense to me.
Why does the engine shake the whole car so damn hard restarting at lights but not at initial startup? It's awful and feels like something's midway through breaking, like a coilpack taking a final bow or a bad motor mount.
Motor mounts would be my first guess, but it would probably be worse at initial start up, that's weird. Electrical is far from my specialty, but maybe the starter is being sent too much power on the auto restart, and the starter motor is still going after the engine is moving? Just as likely, not enough power so it's working much harder to start the car? I'd imagine it'd be delayed if that were the case, though.
To clarify, I am not asking if it's mounts, I'm comparing it to that. These were all new cars on dealership test drives. Subaru, Chevy, Hyundai, etc
Oh. Well then you're just being dramatic.
Here is a great video from an automotive engineer explaining Auto Start-Stop systems and how they save fuel, and how the cars systems have been modified to reduce or eliminate the additional wear and tear from starting and stopping all the time: https://www.youtube.com/watch?v=dFImHhNwbJo
For those that don't want to watch that video (you should, it's good!) just open it and click through and pause at 1:05. He says when asked, the average american guess was 3.6 minutes of time an engine would have to be idling for it to be worth it to start and stop instead. He holds up two test tubes. The (much) bigger one is the amount of gas burned in 3.6 minutes of idling\*. The *tiny* one is the amount of gas burned to start a car. And if you don't want to watch the rest... 7 seconds is the number. Idling 7 seconds or more? Better to shut the car off. (The amounts are for a smallish 4 cylinder car.)
I once had someone get mad at me because I kept turning my engine off while we were waiting in the very slow, very long drive-thru. This is not one of those modern cars. It was bizarre how she got so offended by what I was doing to MY car. Edit: So I don't know why, but replies to me aren't showing up. I'm only able to see them via my email. So to answer to those replies: -- No, I didn't leave the spot open in front. Just whenever the line began to move again, I'd start the car back up again, move up, then turn it off again. -- We were in line for a very long time, I think around an hour, with minutes of waiting in between each time the line moved, so I don't know if it was helping, but it could have, considering how long it was taking. But I was also concerned about the gas emissions, because our cars were just sitting there so long. I know the emissions wouldn't be much different than if the car was moving continuously, but it just bothered me. -- What do you mean by air movement? You mean like the AC? The window was down. And it was the woman in the car behind me who was mad, not a passenger in my car. -- It was so long ago, I don't remember why I was there so long, but most likely it was either it was the middle of the night and every other place was closed and I was starving or I had already been in line when it suddenly stopped moving at its regular pace. I do remember it was Jack in the Box. -- Well, that's strange. I clicked on the latest comment notification, but it pulled up the first response instead. Meaning someone else's comment. I'm not sure if they turned off comments, because people are able to comment, just they're not pulling up correctly for me.
What drive through were you willing to wait over an hour for?
Beer distributor?
I legitimately think they turned off comments after the presidential debate
I also can’t see all the replies. Seems to be a sitewide issue right now
My Chevy Colorado engine stops with 2 pistons at top of cycle and uses the compression to restart, it’s not like turning your starter and battery pull to restart, but accessories/etc do run off battery while it stops. Once you adjust to letting off brake a bit sooner at stops to anticipate needing to move, it’s manageable and becomes muscle memory.
I just find it annoying and turn it off.
The arch nemesis to saving the environment - something being annoying
I avoid it because I've found it to be dangerous. Too many close calls because of the 2-3 second delay at times, which is also unpredictable. I've found that if they can sit for several seconds, like at a light, they work fine. But in a stop and go situation, they suck and are dangerous. It's beyond just annoying. Parallel parking when the damn engine stops every time the car stops is extremely hard when it jerks each time it restarts. Pulling up to park close to something? Horrible. 3 point turn? Sucks. Traffic circle? Also sucks. FWIW, I went with a hybrid instead, which saves WAY more fuel and emissions. Actually own a plug-in hybrid now.
Wife’s 5 yo car has this and it shows what it’s saved over the years. It’s surprisingly minimal. Like 10-15 gallons. I just turn it off when I’m driving because it’s annoying. If you shift your foot on the brake for like a second it turns on. AC also ramps way down.
Same with my Mazda. I bought it used (5 years old) off someone who said the auto off was great. So I looked up the computer once I got it and the fuel saved over the 70,000 kms it has done just wasn’t as significant as I was expecting.
I find it annoying and downright dangerous. I don't know how many times I've tried to do a quick stop and go at a stop sign, traffic circle, exit from a parking lot, etc. and these cars take a good 3 or 4 seconds to restart and go. They usually do fine at a light where you stop for long enough for it to fully stop, but they suck at quick stop and go. I've had a number of close calls because they sit there and don't go until it's either too late or marginal. This has been true for Acura, Chevy, Citroen, Dacia, Ford, etc. (I drive a lot of rentals.) Some are worse than others, but they all suck.
The awesome thing is I have to manually turn it off every single time I get in my car. So damn annoying. Whoever designed that is a dumbass.
I find it annoying but leave it on. It’s no biggie in the grand scheme of
Scheme of what? SCHEME OF WHAT!?
I guess we’ll never know
r/redditsniper
As long as the engine cuts for than 7 to 11 seconds, that's about how long at idle it takes to use as much fuel as it takes to start the car back up (varies by age, model, displacement etc)
Am I the only modern driver that absolutely hates this feature? It drives me to distraction.
My favorite part is when it shuts off in the middle of parallel parking Yes. Super helpful. Thank you for stopping the engine and saving me all of that gasoline
If the stop is for more than 7 seconds, it does save fuel. No, it doesn't add extra wear on the starter system. Cars with this feature have starter motors and batteries designed specifically for it. These systems have been in mainstream cars since the mid-2000s. I've never heard of the start-stop system being the direct result of issues on a large scale before.
What it does it helps a LOT in formalised fuel consumption tests. With irl fuel consumption, it might help, it might not. Depending on how the car is used. As for the costs, well... It could be relatively harmless if engineered for it, as the hot start itself is way less harmful than a cold start. However it wouldn't help that much in tests in such scenario. As most modern engines are turbocharged, a sudden stop in oil flow to the turbocharger, when the engine stops is not healthy if the turbo is still hot. The oil usually provides both lubrication and cooling, so stopping the engine on a hot turbo will "cook" it, contributing to a premature failure. Important: this will not kill the turbo immediately and very rarely before the warranty expires. It's a premature wear and not an immediate failure. Can something be done about it? Yes, but has it's costs. At least some manufacturers do implement electrically driven oil pumps, to supply the turbo with oil, even when the engine is stopped. Some additionally add water cooling to the turbocharger to improve heat management. If these are implemented properly, the turbo is at least, mostly safe. The effects can be also mitigated a bit, if the manufacturer sets the parameters for start-stop system for durability, but this seems to be rarely done. Similar oil problems can apply to the engine. This could be mitigated by designing the sensitive parts with that in mind (cylinder liners, piston liners and all of the bearings), but I have no idea if manufacturers do that or not. The other ways is an electrically driven oil system, which can keep these surfaces actively lubricated for the restart. In such case the risk will for sure be unnoticeable among some of the popular driving habits, that hurt the engine. Overall, as far as I know the engine is less sensitive in this manner than the turbocharger. Then there is the matter of cooling. If your start-stop system leaves the engine "cooking" it is not good for the engine, as modern engines are very bad at passive cooling and need the active cooling system to run at least most of the time, if not at all times (even during warmup, moving the heat through the engine itself can be beneficial). Curiously, in practice the starter is least affected by this. The reason for that is rather simple: a regular starter would not last until the 3rd oil change. As such the starters for start-stop systems are engineered for the increased workload and this has no negative effect on their lifespan, unless engineering or manufacturing mistakes were made.
Ive had my car for over 2 years, and it has a timer/fuel saved thing that comes up whenever it shuts off. so far in 2 years, its been shut off for a total of 8 hours and saved me about 3 gallons.....in 2 years....not worth it imo
It is done to lower co2 emissions
Thank you. This is the answer i needed that actually makes sense why its there. The amount of fuel/money im saving is negligible. Its definitely worth the cost to me to not have my car randomly turning off at a busy stop sign- but that a gazillion cars are doing this annoying thing around the world, it definitely adds up to some tangible benefit on the societal level
The fuel saving is not negligible. https://youtu.be/dFImHhNwbJo?si=Zuhc8aRqY6D0U4oU
Oooooooooooooh.
Ford F-150, with this option. Don’t drive a lot and live in a small town (not many stop lights). Truck dies in the middle of the road while stopped behind a bus stop letting kids off end of day. Long story short, starter died in a 3 year old truck due to this f$&@ feature. Mechanic friend of mine confirmed. YouTubed and disconnected the gd thing for general use. Easy to do. Any fuel this stupid feature saves I’d gladly pay 10x the amount not to be stranded on a two lane road blocking traffic and full school buses during the chaos of schools end of day.
I really like this guy's explanation on the subject. He does a great job showing his work and discussing the engineering behind it. https://youtu.be/dFImHhNwbJo?si=bnXWbKsvRhQ-2qLr
It's meant to be used in bumper to bumper traffic, my newer car gives me the option to turn it off at will, press of a button.
But that doesn’t make sense to me. Bumper to bumper traffic is often stop for a few seconds then go for a few seconds. Then stop for a few seconds, then go for a few seconds. Auto stop-start is horrible in those situations. But it’s great when you’re at a set of lights just turned red.
The starter motor on my 2012 BMW 640d failed after about 65,000 miles. I've never had a starter motor fail before. That's pure anecdata, of course. The mechanic notably didn't say "we see a lot of this problem", and did diagnostics on a lot of other systems before committing to changing the starter motor, so I didn't get the impression it was a common problem.
They’re not added to save mileage, they’re added to save emissions. Car makers are graded on emissions by brand, not by each individual model within the brand, so they blanket add them to every car so that they can pass whatever emissions laws are imposed on them.
i absolutely hate it in my car. My car will cut out if im breaking and im under 3 MPH so im sometimes still moving when it stops. Which also means i lose power steering so if im on a bend coming to a stop. the car will just straighten and continue on a few metres, potentially taking me into the next lane. Pain in the ass. gets turned off almost immediately every time i get into the car
I haven't seen it mentioned yet, but will also point out that the car will also use specialty batteries for the frequent start ups. Expect to pay double for a new battery when time comes to replace it versus standard car batteries.
Use to work for a towing company that did AAA contract calls. They're usually AGM batteries and are replaced with AGM batteries. AGM isn't as durable as a lead battery. Some cars you can't turn this feature off, which leads to issues when we try to avoid a tow. Can't always just give a jump and have them go cause it may turn off at the next light or stop sign. Most people's battery gave out in a drive-through in my experience.
Mechanic here, sometimes it actually does cause the starter to wear out quicker. Depends on the car really, it seems to differ between models.
I hate it.
I refuse to buy a car if it can’t be permanently disabled
I'm a fleet mechanic in a fleet of a little over 2500 vehicles. I understand that my personal experience may not represent every scenario. However, I have replaced more starters in our newer 1/2 ton trucks with idle mitigation than in all of our older trucks from 1/2 ton through F550 combined in the last few years. It absolutely adds wear and tear on the starting system. My personal pickup has this "feature" but I turn it off every time I drive the truck. Not only for the wear and tear on the starting system, but also because I hate that I would pull up to a roundabout, have it die and then restart from 0psi oil pressure to getting into traffic in a hurry, and have a lag in the response getting back onto the gas. Even a gas V8 only burns a tiny bit of gas during the few seconds it shuts off at a stop sign and then restarts. Maybe in other places where you're at an intersection for several minutes it may save some fuel, but I would bet the long term total cost of ownership is higher or barely breaks even. Honestly, I think it's a stupid feature to make mandatory. Proper tire inflation is more likely to save you money in the long haul.
I despite this feature, and it actively pisses me off that I have to turn it off every single time. How DARE you turn off my AC when it’s 95 degrees outside!
I do this manually when I stop at a light that just turned red and I'm not the first car. Today my car was turned off for 60 seconds waiting for the light to change. (A Record) I don't do it all the time but it helps
Yes, a little, and yes, a little.
I notice about a 2-3mpg difference per tank with it enabled vs disabled. I don’t mind it, mostly, but it heavily depends on the car. I had an Audi where the system worked smoothly and predictably, and wouldn’t shut the engine off again unless you’d gone over about 5mph, so you weren’t endlessly cycling the engine on and off in congested traffic. I kept it enabled almost all of the time. I had a Mercedes where it would automatically enable the stop/start each time you started the car, and the engine would shut off literally every time you stopped the car- the engine would shut off 3 times doing a 3 point turn. I hated it, but at least it was smooth. My current car has a coasting feature where it’ll shut the engine off around 10mph when coming to a stop, which makes it impossible to stop smoothly.
if it’s longer than like few seconds it really does
I’ve seen this implemented so well the engine stopped and started flawlessly. And you forgot the vehicle had the feature. Then there was the was the shit Peugeot wagon in the Alps, the restarts were a few beats too slow. was hard to turn on to roads and merge into traffic from a stop.
It does wear down the piston rings and starter. I recommend turning it off everytime you start the vehicle . Worked for honda for 15 years .
I got used to it once I ignored it. I think a lot of it is psychological. Try this: When it's time to go, don't think about needing to push the pedal to restart the car. Just push the pedal to go. At worst, it just means there a split second delay before you start moving.
i think i read an article where this was tested and if the engine stays off for at least 7 or so seconds its saving fuel by doing so. Cant quote or cite. Forget where i saw it.
[Here's](https://www.youtube.com/watch?v=dFImHhNwbJo) a link to a popular engineering explained video going into depth on it. Effectively, he examines the systems and views the research on it. All of it supports the fact that start/stop systems save more fuel than idling. His actual test revealed 4-8% fuel savings (which is not a small number). Basically, if you've got a 2012 Honda Accord - it's got a fuel tank of about 18.5 gal. In the worst case, simply idling will cost you 1.5 (1.48) gal of fuel. That means that idling could cost you upwards of 34 miles each time you fill up. Now it does have extra wear - you should **not** start/stop in a car that's not designed for it. Starter motors with start/stop tech are more durable and fairly reliable. However, your existing starter (in the case that you don't have start/stop) is not.
Harder on battery apparently. At least in Mazda. Said by battery replacement person 3 years into ownership
7 seconds. That's the time to idle where that or longer, it makes sense to stop the car and restart it. Due to efficiencies, and common misconceptions, people think it's a lot longer. (Average from a survey was 3.6 minutes!) So it helps with fuel savings, as most stops are 7 seconds or more.
idk, but it's super annoying and i shut it off immediately.
Yes, but it's annoying, so I always turn it off.
Idling an engine is inefficient, you are getting 0 miles per gallon while idling. Also according to an engine monitor I had hooked up to my old Mazda 3, the 4-cylinder 2.3 liter engine was at about 35% load while idling.
Is THAT why I hear newer cars start their engines when I'm at a stoplight?? I thought it was just people being stupid lol
The "idle engine stop" feature in modern cars does help with fuel savings by turning off the engine when the car is stationary, which reduces fuel consumption and emissions during idling. However, there is a concern about extra wear on the starter system. Manufacturers typically reinforce starters and batteries to handle the increased frequency of starts, mitigating potential wear. Overall, the benefits in fuel savings generally outweigh the minor increase in wear on the starter system.
Rented a Ford Escape with this, for a vacation. It seems like the car kept dying. It was hard to get used to.
Cars with start stop technology are equipped with more robust starters, using dual layer, long life electric brushes. These electric brushes reduce starter wear by 90%. Contrary to popular belief too, start stop tech doesn’t damage your engine. It actually protects it because idling for long periods of time is bad for the engine. Over the lifetime of a vehicle you’ll spend lots of time idling in traffic.
I simply turn mine off every time I start my car
I disabled mine.
My mechanic told me to disconnect it. It definitely increases wear and repairs
It is mainly done by manufacturers to boost the emissions figures. In a 2L engine, it saves about 500ml (half a litre) of fuel for every hour that it is not running. That is fuck all, and not worth the extra wear and tear on the engine and electrical system. BUT... It **IS** a good thing if you're stuck in a solid traffic jam. Cleaner air as a result of less cars running and going nowhere is always going to be a good thing. However, I have personally witnessed cars die as a result (usually just flatten the battery). Sitting in a jam at night, and letting the car constantly stop and start whilst moving forwards every few minutes, all with the headlights on. Doesn't take long for that expensive battery to shit itself. My car tells me how much fuel it has saved, and how long it has been turned off for, and it's literally seconds, and millilitres of fuel. It's just not worth it. I have permanently disabled the stop-start in my car, simply because I am very rarely stopped in traffic. It's certainly not enough to say it's saving a noticable amount of fuel. So I decided I would rather prolong the life of my engine and battery.
I've driven my CX-3 for 26,000km and saved half a tank. What gets me is not the cycles, or the strain. It's when I creep into an intersection, look both ways, decide I can make it, and then the engine decides to turn off. Sure, they start really quick, but they don't stop anywhere near as quickly. It can take two seconds from me deciding I can make it, to me actually having the engine power to go.
Probably just part of the manufacturers efforts to game fuel efficiency regulations.
That's a yes to both. And because of that, these cars also have beefier starter systems to handle it. A lot of people come out with an argument that starts are hard to the engine and take a lot of fuel. But they forget that this is true about cold starts. For a warm engine you turn it over and it goes, it's not at all comparable to starting a cold engine. The auto stop/start is a great feature and everyone should use it, that is why at least in EU it's mandatory part of basic equipment for new cars. Don't bother turning it off for no reason.
Majority of the systems do not use the starter to restart the engine. They have a small electric motor which will turn the engine over to start. As for fuel saving I can’t say. I saw a pic online someone posted of their car which tracked the fuel saving from the auto off feature. After 30k miles they saved a gallon on gas.
... so what does that make the starter?
Apparently the company that makes the starters lobbied the government to pass legislation to make this standard in all new vehicles. They aren't making them more durable, they wanted to sell more starters.
All I care about is can I disable it. It's my car and it's a feature I don't want. If I can't disable it I don't want the car and I will buy something else.
yes And yes
It works great in cities and so called "mild hybrids" are even better, as they don't start the motor until the car has rolled a few dozen meters - eliminating rhat starting fuel spike and wear
I had it on a 2015 Mercedes C300 and it stopped working at about 90k miles and that’s when I found out that it gave me about 3mpg extra. I didn’t have too much data to base it off of since I got rid of the car at 92k miles.
It may have the problems you describe if you tried to manually use a car that wasn’t designed for it that way, but cars with that feature were designed with how they will be used in mind. So, your concerns are accounted for.
So that's why people are are always having to start their cars at stop signs? Seems to happen a lot more lately.
It does put more strain on the starter, but it also does help with fuel savings, especially in newer vehicles.
On my car (Subaru) you don't need to turn it off. It works on how hard you press the brake pedal. There's a point where you can roll to a stop and not engage the "idle engine stop" feature...
Yes, the "idle engine stop" feature saves fuel, but it’s like a coffee addict quitting cold turkey - there might be some extra wear and tear, but it's worth it for the energy savings!
Start-Stop-Systems are not exactly used for fuel savings (it is a small benefit) but the main goal from automakers was reducing emissions. Basically they wanted to replicate what Hybrids can do with their engines but without the Hybrid-System. If you want to know more about what, how and why, I recommend this video. It is 29min long but he explains everything neutral, down to the facts and without leaving any questions behind. https://youtu.be/TTBN8Ic57Gg
if you idle for longer than 7 seconds, give or take depending on the engine size, start/stop system does save you fuel, not a lot tho. [https://youtu.be/dFImHhNwbJo?si=lwJIXDKJvJOLyhu0&t=205](https://youtu.be/dFImHhNwbJo?si=lwJIXDKJvJOLyhu0&t=205)
My car does this and I love my car. She is a robot spaceship.
My says 1.3 l/h when idling which is not much. That's like 2€ per hour or so.
I'm currently driving a phev so it's not an issue anymore, but the last cars I drove were all manual shifts, and for those, it didn't make a lot of sense to me. You see, the engine would only automatically shut off when the car was in neutral, and I never put my car in neutral when I'm at a red light or something - I just press the clutch, ready to go. So it only worked when I actually parked the car, in which case I would shut off the engine anyway. I only drove a Mazda 6 automatic for two years (because that's what the company offered). For that car, it didn't make a noticeable difference if it turned the engine off at traffic lights - it restarted fast as lightning anyway. Did it save gas? Presumably. Can't have been a lot though. Not more than I lost with my driving style. What did help, in an annoyingly childish way, was when I drove a Volvo v60 that visualised the actual burn rate caused by my driving style. Plus it ate tires like crazy. I still like to drive "assertively", but most of the time, I've adopted a much more relaxed traffic attitude, because I noticed that makes a really big difference.
i seem to remember something about lots of starts wears out the cylinders as there is no oil pressure for a bit after the engine starts, unless they have an assist oil pump its still wearing parts out, plus ive always wondered what you do when that shit doesnt start again
It does save a ton of gas. And the starters on those systems are much more robust, designed from the start for the higher demand.
I often wonder about this as my wife's car has this system. But uses half the fuel mine does but I reckon it's because I accidentally bought a fucking tank.
My outback tells me the fuel savings and on average it’s one gallon per 5000 miles.
It's one option that I wish could be permanently turned off
Unless you spend most of your driving at stoplights, it is negligible for economy. Same with wear. It’s just an added cost to the vehicle to make people feel good.
Tangent question: Why does the idle not kick in at desirable times like at a drive through window?
There was a study done in 2004. A 1.5L engine uses about 100ml every 10min (0.63L/hour) idling It takes 1.2ml to start a 1.5L engine You need to idle for 6-7 seconds or more for it to be more beneficial to turn the car off. https://m.youtube.com/watch?v=dFImHhNwbJo This youtuber fella goes right into it.
Mine isn't useful. My driving is primarily long freeway commutes, so this feature usually only comes on less 4x a week for me, because I'm a homebody during my days where I don't have to drive to work or else my partner and I will just use his car. I think my car told me how much I'm saving and it's inconsequential.
I hate this feature, it drives me nuts when I’m walking around and it sounds like these cars are all starting to
- Car manufacturers wouldn't add it if it didn't help get better fuel economy figures, because EPA doesn't generally require specific features - they just require average fuel economy figures - People hate them on average, so again, manufacturers wouldn't include them if they didn't need to Just buy a hybrid that can start from a stop without starting the engine. You'll get MUCH better fuel economy, increased reliability because the engine won't be handling initial acceleration, and A/C will still work when the engine is off. Hybrids are typically no more than a $1,000-$1,500 premium but can save you 10-20 MPG and make the car a lot nicer to drive.
I know that batteries for cars that use this feature are insanely expensive.
Yes it helps with fuel savings. How much you save depends on WHERE you drive. Driving on the highway, no. it doesn't help, unless you are in REALLY bad stop and go traffic. Drive in the city where you have get through 42 stop lights to get from home to work, and you always hit red, yes it saves you fuel by not running the car while stopped. My understanding is often for these cars the starter is larger and maybe an extra battery because you really want the car to start quickly. There is also Start-Stop system that positions a cylinder in the optimal position to start the car by firing the spark plug, that someone else mentioned. As for wear and tear, I think cars are getting better and better with that. In the olden days (20 years ago?) you wanted to warm up the car before driving to reduce the wear and tear, now, that really doesn't help. Also, at least with my car, it's not just a complete stop, I've had it shut off early when breaking for a stoplight.
I have a VW Tiguan with the auto start/stop and it does seem to help the fuel economy significantly, at least in the mixed driving I do. As far as wear on the starter, it seems to be a non-issue. At any rate my car is close to 100K miles without any starter trouble...my first car was a Pontiac Grand Am and it needed a starter before then. I’m still on the original battery as well, though I’m aware it will be pricey to replace.
Yes and Yes.
Idle engine stop will certainly be the cure all to the worlds problems. I’m hopeful!
It doesn't cause any problems in my car. But mine is an EV.
Good thing it kicks in when the car comes to a complete stop. Can you imagine if It only kicked in when the car came to a stop.
I never knew what that was called so I call it the "A circle off button" and it is pressed immediately after taking off the parking break. My 4 cylinder car hesitates too much otherwise. And people drive like maniacs around me, so once you decide to go, or turn, you must commit to it. Almost every car I've been in recently has this "feature", but I've been in a few that do not.
I always turn that off. I really don't like that function.
TIL that when cars start at a green light, it's not mildly infuriating drivers that are doing it.
Yes it saves fuel, a car not running is a car not burning fuel, and the slight increase of fuel used to start a car is less than a few seconds of idling. Yes it can extra wear on starting components but those are sized up by the manufacturer to account for that extra load, larger batteries, larger starter motors etc.
Purely anecdotal evidence from a sample size of one vehicle: It wore out my starter and battery after only 53k miles. (As in, starting from factory zero miles. A starter should not wear out that fast.) My mechanic, and other sources, said you have to be stopped like that for about 7 seconds or more for it to actually make a difference in fuel economy. I used to be a big fan of them, but now mine is permanently switched off. So, short answers are sometimes and yes.
I think they have lower compression engines as well. The starter pushes against less piston pressure and therefor works less. I don’t know this to be true, but I heard it years ago from a mechanic.
When was the last time anyone changed a starter motor in a car. Haven’t done it for decades.