did take about 10s for it to restart

That sounds broken. In our Polo I can’t beat it restarting however hard I try, as soon as your foot moves the clutch pedal it starts.

My emissions are low anyway, what with the car sat on the driveway unused.

There’s a good chance this is linked to it not being activated. If your car sits around the battery is probably a bit low and it will disable itself.

I’ve never driven an auto with it, but in a manual all the concerns of it not being ready at busy junctions etc just aren’t an issue, because you’d sit at the junction with the clutch in ready to pull out. Those that say they cut out at awkward times are they autos?

I don’t drive the Polo that often so I do still get confused occasionally that it’s gone very quiet because I forget it has it.

Out Kia Ce’ed is an auto with stop/start; works seemlessly, restarts as soon as you start releasing tension on the brake pedal long before your foot reaches the accelerator.

Just to be clear, I’m all for cutting emissions. So it’ll get used.

I’m just concerned about longer term reliability and wear issues.

The air-conditioning thing boils down to how cold is it supposed to get…I suppose.
Kids, new toys etc…🙂

setting off before belting up

£60 and a chat to a nice policeman did wonders for breaking that habit for me. He was just at the end of my road.

I “had” to drive a short distance last week without a belt on because it had jammed and wouldn’t pull out, felt pretty weird to bit not have it on. (I’m not That Old.

All these people worried about pulling out at roundabouts in a hurry after the stop/start has engaged: Why are you sat in neutral with the car out of gear if you’re expecting to pull away at a moments notice?

It’s been around for more than a decade now, if it lead to lots of issues down the road I guess we’d know about it by now.

My new (to me) car has it, it’s also an auto. If I had to moan than mines a bit too keen, being an auto there’s not need to put the handbrake on or anything if you drop below 2mph it cuts, even if you’re not actually stopping, which also cuts the power steering, it’s not been an issue yet, but moving around parked cars in the supermarket and it’s cut out, it’s a bit frustrating. On those busy roundabouts when there’s a 20 limit and everyone feels the need to do 40 you get used to giving the pedal a bit of a tap to wake it up before you go.

I can’t complain too much though, my new car is bigger, faster, auto and 4×4 (it’s saloon not an SUV) and yet it’s more efficient and less polluting than the last one, which wasn’t bad either.

The green yellow orange lights to suggest how you are driving really are rubbish though

This does sound like modern toss..! My ’11 plate has no such lights 😆

To those that say “I use it” just pull up to a junction and open your window.

Count that cars that roll up-engine stops-and immediately starts again on tick over for 5mins waiting for the lights to change.

Of the ten cars next to me this morning, 9 cut out and immediately started again.

I personally think the technology is brilliant and should be compulsory on all vehicles, but until Mr/Ms angry 1Series or MrDPDelivery bloke actually uses it.. we’ll continue to burp gas out of vehicles all day long.

if you drop below 2mph it cuts, even if you’re not actually stopping, which also cuts the power steering

that does seem a bit keen – is that how it’s supposed to work, cut out every time you pause in a maneuvre?

On my car even trying to turn the wheel will restart the engine, though.

I think the stop start thing is just a gimmick by manufacturers. I could be wrong but doesn’t it use up more fuel stop starting an engine multiple times in a short distance,

Er, you are wrong. Even for a small stop at lights, it helps – I know this because when the battery’s low (if I haven’t driven for a week or two) or I put the blower on harder when it’s just started it doesn’t kick in and the fuel economy is worse.

The amount you’ll save in fuel over the life of a starter motor will pay for the starter motor. The chances are older starters will fail from general age (corroding to bits etc.) rather than over-use. They are designed and tested for this use after all!

I find even at the front of the lights it’s so quick to start I just dip the clutch as the light goes amber and go when it’s green. No need to keep the engine running even at the front of a queue. If it’s not starting immediately there’s probably something up.

Had a 2009 Freelander 2 with it, started only working sporadically a few years in as it decided the battery wasn’t 100%, or the ambient temperature wasn’t quite right or something. When it did work it was a little annoying because it did not start quickly enough – you had to pause a moment after clutch down – and as I was used to it NOT working I didn’t allow the time for it to start… Sold it last year (9 yrs old) with its original battery and original starter, the only think that went wrong on that car was a wheel bearing.

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Got a 2013 golf with it, barely notice it. Starts before clutch down and gear selected.

This had immediate and total battery failure (Moll brand) one day last year (5yrs old). Stopped as usual at a busy junction then just didn’t start. No battery juice to run warning flashers or anything.

Had to negotiate someone to stop traffic and help push it out of the way. Not fun. New battery was about £70 from tayna.co.uk

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Mum has a 2015 Skoda Fabia with it. “Low battery” warning strated popping up and it turned stop start off itself last year (3yrs old) Moll brand again. I fitted a new battery to be safe.

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Overall I think its great, why sit there burning fuel polluting the air in traffic jams / queues?

Oh and these batteries weigh a tonne, so get down the local metal merchants and weigh it in for more than a tenner back.

Had SS on my Fiat for 9 years and it worked very well. If the battery is not fully charged it will keep idling or stop then restart after a few seconds but then i do lots of short journeys.

My current car has it too and it works just as well, though I turn it off on short journeys to warm the engine up. (DSG which is awful until everything is warm). Never again.

There’s some evidence that start/ stop increases pollution. This is because it reduces the temperature of the catalytic convertor, leading to increased NOx emissions. The study I read was only for one car mind, so more research is needed.

That’s generally not true, especially in diesels – the flow of (relatively) cold exhaust gas at idle will transport heat out of a catalyst whereas engine off the thermal inertia in the cat with no gas flow will keep it hot. Some gasolines there is maybe an ounce of truth if the catalyst hasn’t fully lit off, but stop/start will be inhibited during initial catalyst heating anyway so is a non issue.

Stop/start is a very mature feature with plenty of solid engineering around it – no reason to not use it.

The ‘safety’ concerns are just a non-thing: usually stemming from ‘i pull up to a roundabout and it cuts out just as I need to pull out quickly’ – if you NEED to pull out that quickly it’s probably not safe to do so anyway, just be patient or plan further ahead.

Had it in various manual and auto cars, always liked it. Current one is a 6 year old Octavia, press break fully and the engine is off, lift slightly (e.g. getting ready to move at a roundabout) and it starts again so you’re ready to go. Nice n simple (and doesn’t take a fictional 10 seconds)

if you drop below 2mph it cuts, even if you’re not actually stopping, which also cuts the power steering

that does seem a bit keen – is that how it’s supposed to work, cut out every time you pause in a maneuvre?

I’m not sure, it’s a bit too clever for it’s own good sometimes. If you’re travelling at say 30mph and start braking (especially if it ‘sees’ a car in front) it’ll assume you’re coming to a stop and cut (below 1 or 2mph) and 90% of the time it’s right. But sometimes if say you’re making your way through a busy road with car either and you have to take your turn waiting to go etc, sometimes just as you’re shuffling through it’ll cut, restart is about a second but there that little moment when you’re still moving (very slowly) when you suddenly can’t steer.

It’s supposedly adaptive, either I’m adapting to it, or it to me, but this sort of stuff is happening less and less.

if you drop below 2mph it cuts, even if you’re not actually stopping, which also cuts the power steering

that does seem a bit keen – is that how it’s supposed to work, cut out every time you pause in a maneuvre?

On my car even trying to turn the wheel will restart the engine, though.

Most systems these days will cut out just before a stop if your deceleration gradient is low enough. It does help to save a fraction more CO2 and modern engines start so quickly you usually won’t notice any difference ( although as mentioned above my DSG golf didn’t like it when the transmission was cold…)

Cars with hydraulic power steering will generally restart if the wheel is turned greater than a certain angle, or at a fast rate of turn; this is because the engine is needed to supply the required PAS pressure. It can happen with cars with ePAS as well but generally to a lesser extent unless the battery voltage is low.

Apologies if this has been done many times.

It has.

I could be wrong

You are. I can’t remember offhand the exact time where you have a net gain in start/stop over keeping the engine running, but it’s in the order of a few seconds.

Stop/start is a mature technology and a lot of companies have invested a great deal of money into its research and engineering. Don’t you think that someone, somewhere might’ve considered any potential extra wear to a starter motor / battery and compensated for that? The last time I had to replace a starter motor was in a 1977 Ford Fiesta. You don’t want to “wear out” the starter motor, so you’ll take additional wear on pretty much every other component in the engine instead? Bunch of luddites on this forum, I tell you. (-:

Neat thing on mine that I only noticed after about a year of ownership: the start/stop is tied in to the front parking / adaptive cruise control sensors. Stopped in traffic, if it sees the car in front move away it’ll start the engine, I don’t even need to go anywhere near the clutch.

Oh yeah, and,

Nice n simple (and doesn’t take a fictional 10 seconds)

If it’s taking 10 seconds to start, it’s broken.

That’s generally not true, especially in diesels – the flow of (relatively) cold exhaust gas at idle will transport heat out of a catalyst whereas engine off the thermal inertia in the cat with no gas flow will keep it hot. Some gasolines there is maybe an ounce of truth if the catalyst hasn’t fully lit off, but stop/start will be inhibited during initial catalyst heating anyway so is a non issue.

I was reporting on results from actually measuring exhaust gas emissions, so I wouldn’t dismiss it as a non-issue. As I said, this was a single sample, so some further research is needed.

Works fine on my Passat and I’m pretty sure it improves economy (if only slightly) and of course it reduces fumes from stationary vehicles (well every little helps). My only criticism is that it doesn’t work when tow bar electrics are attached (even for a bike rack).

I was reporting on results from actually measuring exhaust gas emissions, so I wouldn’t dismiss it as a non-issue. As I said, this was a single sample, so some further research is needed.

My day-job is calibrating car engine ECUs and although this is always a consideration, it almost always is a non-issue. There is always far more trouble with too-cold exhaust gas flowing through a catalyst cooling it down than heat lost from long stop-start periods. Once a catalyst is properly lit off then the thermal inertia is high enough that with no gas flowing through it will stay at temperature. Stop/start systems will generally restart the engine after a couple of minutes and the temperature lost during that time will be a small handful of degrees and then drop much more considerably when the engine is running. As mentioned, this is especially true for diesels where the idle exhaust temperature is very low, whilst a gasoline exhaust gas at idle is generally hot enough to not cool the catalysts too much.

The above isn’t meant as an ‘i’m right, you’re wrong’ – as you say it is just one report and in the report circumstances it may be true, but from experience of doing this as a job, the temp drop during stop/start is not an issue and vastly outweighed by the fact you aren’t producing any emissions at all when the engine is off.

Stop/start is a mature technology and a lot of companies have invested a great deal of money into its research and engineering. Don’t you think that someone, somewhere might’ve considered any potential extra wear to a starter motor / battery and compensated for that?

And yet they continue to get it wrong. DMF, DPF, fuel injection systems classed as disposable etc.

And despite what anyone says, I’m still not sure how turning an engine on and off, particularly at lower temps can be any good for it?

I’m happy to be proved wrong,

You don’t want to “wear out” the starter motor, so you’ll take additional wear on pretty much every other component in the engine instead? Bunch of luddites on this forum, I tell you. (-:

No, I’d rather understand the consequences of half a million additional engine starts.

Its not about whats good for the engine, but they do test and design to mitigate , if you cant be convinced by the by the knowledgeable and in-industry posts above then perhaps save a couple of quid a month for the death in service starter motor , BTW they have changed in design since the old Fiesta so can cost a bit more now.

Did I miss the half a million additional starts?

Say 20 year engine life is about 68 starts every day. Is that what people are seeing?

And despite what anyone says, I’m still not sure how turning an engine on and off, particularly at lower temps can be any good for it?

Nor am I, but my lack of understanding doesn’t mean it must be bad.

Say 20 year engine life is about 68 starts every day. Is that what people are seeing?

My commute on it’s own has well over 60 (both ways – town, motorway, minor roads.

Nor am I, but my lack of understanding doesn’t mean it must be bad

I didn’t say that. 🙂

Everything has advantages and disadvantages.
I am interested in how, in engineering terms, things have been improved.

Every day for 20 years?

Stop start engines will also have auxiliary systems designed to prevent the additional wear that accompanies constantly starting the engine up. These could include: secondary electric coolant and / or oil pumps, roller cam followers, water jacket cooled turbos.

There’s also the control software which will only engage stop/start when the engine is sufficiently warm, when the battery is above a certain charge status and when high power consumers are not required, such as heated windows, window demisting or cooling of the cabin or power steering assistance. There’s a load of thought gone into it. Shame the system on my kodiaq constantly engages just before the car comes to a halt then disengages as soon as you release the brake pedal (it’s an auto handbrake).

Stop start engines will also have auxiliary systems designed to prevent the additional wear that accompanies constantly starting the engine up. These could include: secondary electric coolant and / or oil pumps, roller cam followers, water jacket cooled turbos.

There’s also the control software which will only engage stop/start when the engine is sufficiently warm, when the battery is above a certain charge status and when high power consumers are not required, such as heated windows, window demisting or cooling of the cabin or power steering assistance. There’s a load of thought gone into it.

Absolutely – the strategy to determine when a vehicle is allowed to stop/start is pretty complex and it’s not allowed if it will impact any systems that reduce emissions (e.g. during catalyst heating phases) or if ambient or engine conditions are outside of certain ranges, etc.

And despite what anyone says, I’m still not sure how turning an engine on and off, particularly at lower temps can be any good for it?

Engines really aren’t that fragile. Some of the robustness tests we do are absolutely brutal and a well designed engine will survive hundreds of continuous hours of this sort of testing. Even the notion of having to ‘break in’ an engine isn’t really a thing any more for a non-high performance car.

Thanks. 🙂

Our car (diesel Skoda Roomster) is now ten years old and while it doesn’t have stop/start I can’t honestly remember if it was even an option on our particular model at the time. I’m not sure how much use it would have had in that time as we live in a rural location and do very little urban driving. If the next car has it, then it has it.

Car manufacturers have a lot of data on how their cars get used so the whole starter system will have been engineered with X cycles in mind plus some contingency.

As above – I can’t remember the last time I had a starter motor replaced and most of my cars have had at least 150,000 miles on the clock. Possibly the Vauxhall Cavalier I sold on in around 1995.

https://www.autocar.co.uk/car-news/new-cars/stop-start-long-term-impact-your-car-s-engine

For those turning it off, your car and it’s starter motor and battery were sized to deal with start/stop, so you’ve paid more for a more robust battery and starter and are no longer reaping the rewards of its intended purpose – to increase your fuel economy.

I wouldn’t worry. Long before 2029 you won’t be allowed to drive an ICE car in many built up areas anyway.

Start / stop is seamless in my EV.

The ‘safety’ concerns are just a non-thing: usually stemming from ‘i pull up to a roundabout and it cuts out just as I need to pull out quickly’ – if you NEED to pull out that quickly it’s probably not safe to do so anyway, just be patient or plan further ahead.

True in the ideal world, but we’re humans and make largely emotional decisions rather than logical ones so common sense like this doesn’t always play out…just like that impatient person who NEEDS to pull out into the outside lane of the motorway as soon as they join it only to get to the car in front a few seconds earlier…that impatient cyclist who runs the red light because they can’t be bothered to stop or are chasing the Strava time, just like the person who just has to read that text when the notification sounds and, despite all their knowledge and understanding, pick up the phone to take a look. And in my case my concern is not me not making the gap in the traffic I wanted to accelerate into, its the person behind me thinking i’m about to go, who is looking right and is not expecting me to hesitate at the junction and rear ends me and shunts me out into the junctions. It happens every single day at roundabouts and junctions – one of the most common types of crashes. I just disable the stop start when approaching the busy junction and re-enable it once I’ve pulled out. All goes nice and smoothly then.

Mazda have a cool system for this. It leaves the pistons in exactly the right place so the engine can restart in half the time of other companies systems.
https://www.mazda.com/en/innovation/technology/env/i-stop/

My son is just getting used to his new 1.2 TSI Fabia Monte Carlo (learnt in a Diesel Audi A1), so has stalled a couple of times as the diesel needed next to no gas on clutch up. The stop start has actually restarted the car before you have had time to think ‘Oh I’ve stalled’.

As a cyclist and pedestrian I appreciate the engines going dead and the fumes stopping for a while while I wait behind or next to the vehicle at lights. Good idea.

That Mazda istop tech is stunning. Proper out of the box thinking.

Some of the robustness tests we do are absolutely brutal and a well designed engine will survive hundreds of continuous hours of this sort of testing.

Mate of mine tells tales of mis-programming engine dynos for overnight runs: once they found the dyno parked in the office above the test room after accidentally telling it to hard stop a locomotive engine. Engine was having none of it. They did the same with a very expensive prototype flat plane v8. Dyno won that one. They didn’t let on to their error and the manufacturer went away and re-designed the crank.

are no longer reaping the rewards of its intended purpose – to increase your fuel economy.

… to reduce emissions.

and is not expecting me to hesitate at the junction and rear ends me and shunts me out into the junctions. It happens every single day at roundabouts and junctions

I’ve driven start/stop vehicles on and off for maybe a decade and this has never happened to me. If it’s causing problems of this nature then there’s something very wrong with either the car or your driving. I’ve had it cut out at the wrong time a handful of times, generally when I’m about to stop and then the lights change or some such, but it restarts so quickly that it’s always been a non-issue.