Well, I remember back in the 1970s having to push start a police car that was used for house calls by the duty inspector, and had done just over 30_000 miles. This had been enough to wear out the ring gear on the flywheel!

Fair enough, but I'll remain unconvinced.

18 minutes ago, BigEjit said:

I have the stats!!

Remember the old saying - lies, damn lies and statistics

 

Sadly those stats don't match with my 40+ years experience of car ownership. The maximum life I have ever got out of a car battery is 6 years - owned from new so I know it wasn't abused or suffered deep discharge. The vast majority of batteries have only lasted between 3 and 5 years before being unable to provide enough cold starting current for a winter start - even an AGM battery that was massively over-rated (cold climate diesel battery fitted to a petrol variant) only lasted 4 years in my other car (a Citroen C1) - which doesn't have stop-start.

Broken ring teeth: in the 70s, the starter had an inertia system that smashed the starter pinion into the ring gear when the starter motor started to spin and that would eventually knock a tooth out. But there would be four teeth around the ring gear that naturally aligned with the starter motor when the engine came to rest, and the same unfortunate teeth would be in the firing line the next time the starter was used, hence the failure of maybe just one tooth but also the reason that the starter pinion would often hit the same gap in the teeth. You had to put the car in gear and rock it a little to realign the starter and ring gear. For a long time now, 'pre-engaged' starters are used where the pinion is engaged with the ring teeth before the starter motor is energised for exactly this reason. 

We fit about 20 batteries a week.

I have replaced a battery at 6 months old on a new vehicle before now.

I would say you are very lucky if you can get 10 years out of the OE battery.

4 to 8 years I would expect.

 

Thanks AG Falco

 

5 hours ago, Gumby said:

  The system will stop the crank shaft etc in such a position so it’s as easy as possible to restart when needed, whilst causing the least amount of stress on the engine. 

 

Do you really believe that?

 

How does it do that?

On 14/01/2019 at 11:33, lmp said:

1:  I have few concerns about life expectancy of some parts of vehicle if started something 20 or more times per day. 

 

2:  concerns are about batteries life and starter systems life. Perhaps there are even more systems having greater load because of that.

 

3: real impact on efficiency and ecology, is there any improvement at all?

 

4:  I think start-stop is best of the best options, isn't there any way to make it stop engine even if comfort temperature is not reached yet.

 

My answers would be:

 

1: Stop/start has been available on many cars for many years now and there is no evidence that shows life expectancy has been reduced because of stop/start.

 

2: As per above - batteries in stop/start cars are more powerful. You can argue they're more expensive to replace but their performance is no different from a non - stop/start system.

 

3: There's very little impact on fuel economy but stop/start means less emissions.

 

4: It has nothing to do with your own personal comfort. An engine is very unefficient when it's cold therefore the sooner it reaches operating temp the better. It's a very bad idea to continually perform cold engine starts as that definitely would have an impact on an engines life expectancy.

Edited 15 January, 20197 yr by Guest

11 hours ago, Scot5 said:

4: It has nothing to do with your own personal comfort. An engine is very unefficient when it's cold therefore the sooner it reaches operating temp the better. It's a very bad idea to continually perform cold engine starts as that definitely would have an impact on an engines life expectancy.

 

I was thinking about engine wear. When the engine is up to temp and stop/start kicks in and stops the engine, the oil drains back down and when it restarts the oil has to recirculate again. This will be one of the reasons it only kicks in when the engine is warm. But does that put extra wear on the engine? Or does the oil not drain back down for the few minutes it might be stopped?

^^^ Except Stop / Start does not only kick in when the Coolant / Oil is warm.

It can kick in 50 feet from me starting after wiping ice off my glass.   Euro 6 TDI SCR DSG and also other vehicles VW Goup or others.

What might make the difference is the setting of the Interior temp compared to the Ambient. (16*OC),  but if not whaked up to 18 but still on LOW that does not Inhibit Stop / Start.

The AC is not on, and the big battery is fully charged from when it was parked up.

14 hours ago, J.R. said:

 

Do you really believe that?

 

How does it do that?

I would hazard a guess the crank shaft position sensor would play a part in it?

38 minutes ago, NikTheGeek said:

 

I was thinking about engine wear. When the engine is up to temp and stop/start kicks in and stops the engine, the oil drains back down and when it restarts the oil has to recirculate again. This will be one of the reasons it only kicks in when the engine is warm. But does that put extra wear on the engine? Or does the oil not drain back down for the few minutes it might be stopped?

 

If you were thinking of engine wear then check my answer 1:  - having been around for sometime now, there's been no evidence stop/start causes extra wear on an engine.

35 minutes ago, Skoffski said:

^^^ Except Stop / Start does not only kick in when the Coolant / Oil is warm.

It can kick in 50 feet from me starting after wiping ice off my glass.   Euro 6 TDI SCR DSG and also other vehicles VW Goup or others.

What might make the difference is the setting of the Interior temp compared to the Ambient. (16*OC),  but if not whaked up to 18 but still on LOW that does not Inhibit Stop / Start.

The AC is not on, and the big battery is fully charged from when it was parked up.

 

I've never driven any car, VW or not, where stop/start kicks in 50ft after starting from cold.

 

Just wondering tho...  why are you driving off with interior temp set to cold after having scrapped ice off your car?  Are you a penguin? 

Edited 16 January, 20197 yr by Guest

52 minutes ago, Russ77 said:

I would hazard a guess the crank shaft position sensor would play a part in it?

 

Hazarding a guess is a bit different from making an authorative statement : The system will stop the crank shaft etc in such a position so it’s as easy as possible to restart when needed, whilst causing the least amount of stress on the engine. 

 

Were it able to do so the crank sensor would play a part but while you are hazarding guesses what is going to stop the engine in an exact position? An electromagnetic brake? A stepper motor to increment the engine to the exact position?

 

My 13 year old PD engine already has a quick start system using the cam position sensors so as to start the engine in 1/2 a revolution.

2 minutes ago, J.R. said:

 

Hazarding a guess is a bit different from making an authorative statement : The system will stop the crank shaft etc in such a position so it’s as easy as possible to restart when needed, whilst causing the least amount of stress on the engine. 

 

Were it able to do so the crank sensor would play a part but while you are hazarding guesses what is going to stop the engine in an exact position? An electromagnetic brake? A stepper motor to increment the engine to the exact position?

 

My 13 year old PD engine already has a quick start system using the cam position sensors so as to start the engine in 1/2 a revolution.

 

At no point did I suggest I was making an authoritative statement, I'm not a mechanic/engineer (far from it) but I'm pretty sure the engineers that designed the car and SS systems would take into account the least stressful way to make the system work.

 

I've heard/read a number of sources that have suggested the engine will pause in a state were there is as little stress as possible to restart it although this would probably only apply to more recently manufactured cars/engines.

 

As with anything, design & technology changes over time with improvements being made along the way. I would assume the first wave of SS technology used was a little more agricultural than what's in place today.

@Scot5, because lots of morning like this winter i am driving off in low temperatures and have the windows down and Recycle air on and temp in car turned down.

The Oil takes 6 miles to even get to an indicated 50*oc,   but it can be nice cold fresh days.

 

I have a Greenhouse heater in some cars when parked up and no ice on windows inside or out, 

and on the SEAT TDI it easily gets ice inside, but then i am wearing outdoor clothes on cold mornings and on a fresh morning it is lovely to get some cool air.

 

It hardly matters if your car can stop / start right after starting off, plenty others can.

I usually press the Stop / Start to off the first time it stops if i am just away to drive through the town, ie turn left. 

If turning right and heading to the countryside i will leave it on.

 

Bellow.

An example of 50 feet from stating off to junction.  Snowy obviously, but no snow this year so far.

Plenty below freezing days though and stop /start will work every time if Heating setting is not up, which there is no point doing as it is 2-3 miles of driving before any heat comes into the car from the heater and that is set onto the windscreen.

Edited 16 January, 20197 yr by Skoffski

Russ77, unless you had preceeded the statement The system will stop the crank shaft etc in such a position so it’s as easy as possible to restart when needed, whilst causing the least amount of stress on the engine.  with "I imagine" "I would think" etc then it could only be taken as an authorative statement by someone without enough knowledge to question it.

 

Now I am not saying authoratively that the system does not do as you say, my knowledge is well out of date, but if it does I would like to know how it does it and indeed why because my 13 year old PD engine starts every time in half a rotation.

Edited 16 January, 20197 yr by J.R.

^^^^  Best do some more research then on the Euro 6 TDI or TSI, google / search engines will be your friend.

 

eg Taken just now.

Car not turned a wheel,

Stop / Start enabled,  car / engine stone cold, just started and stop / start functions because ambient temp and heater setting are not 16*oC different.

Edited 16 January, 20197 yr by Skoffski

10 minutes ago, J.R. said:

Russ77, unless you had preceeded the statement The system will stop the crank shaft etc in such a position so it’s as easy as possible to restart when needed, whilst causing the least amount of stress on the engine.  with "I imagine" "I would think" etc then it could only be taken as an authorative statement by someone without enough knowledge to question it.

 

Now I am not saying authoratively that the system does not do as you say, my knowledge is well out of date, but if it does I would like to know how it does it and indeed why because my 13 year old PD engine starts every time in half a rotation.

OK JR......

@SoupDragon - You're quite possibly right; I remember it for the obvious (even to a 9 year old) embarrassment of the inspector who was asking for a push start.

Everything here is hearsay and conjecture. It took me all of 10 seconds to Google it and find this link, along with dozens of others: http://bestride.com/research/buyers-guide/does-auto-stopstart-technology-wear-out-engine-components

 

This is the final paragraph:

 

In the short term, though, you don’t have to worry too much about whether your engine or its various components are being damaged by frequent starts. They’ve been engineered for it, and they’re different than the components in a vehicle without this technology.

1 hour ago, maffyou said:

Everything here is hearsay and conjecture. It took me all of 10 seconds to Google it and find this link, along with dozens of others: http://bestride.com/research/buyers-guide/does-auto-stopstart-technology-wear-out-engine-components

 

This is the final paragraph:

 

In the short term, though, you don’t have to worry too much about whether your engine or its various components are being damaged by frequent starts. They’ve been engineered for it, and they’re different than the components in a vehicle without this technology.

 

Oh how much we rely on the web these days...

Edited 16 January, 20197 yr by briskoda1

If we’re using journalist articles as sources of evidence then this:

 

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

 

quote

 

“With low-friction bearing and lubrication technology in place the potential threat to engine life by stop-start systems should theoretically be overcome. But the current technology is still relatively new and only time will tell whether every car manufacturer has got it right.”

 

 

Bit more reliable:

 

https://pdfs.semanticscholar.org/fc16/33b1e2edc2acb996aa8792e2c1a607c65e7b.pdf

 

habe a look at findings and conclusion. 

The longevity of Euro 3 and 4 VW Group Petrols and diesels without stop start will get compared at some point to Euro 5 & 6 with Stop Start.

 

Obviously the crap pistons, rings, water pumps, timing chains and tensioners, emissions systems, software etc that VW Group have been procuring and using over the decades and the lemons they have built and then discontinued will skew the results of premature failures due to stop start.

On 15/01/2019 at 16:41, KenONeill said:

Well, I remember back in the 1970s having to push start a police car that was used for house calls by the duty inspector, and had done just over 30_000 miles. This had been enough to wear out the ring gear on the flywheel!

Many Police Inspectors wore out ring gear in the 70's but, there's no historic sex offences being looking into by themselves.

 

Wonder why ?