Reminded why STOP/START is nonsense

[Tech1e]

3 minutes ago, silver1011 said:

Have they, on all models?

 

Citigo they certainly have, not sure about others.

[silver1011]

If they implement the change on the Kodiaq I'll be investing in OBDeleven...

 

https://obdeleven.com/en/

 

And doing this...

 

"Permanently Disable Start-Stop

 

Available with VCP (Vag Can Pro) as an OCF (One Click Function)

 

Works with VCDS as below

 

·         Go to Module 19 (Can Gateway)

·         Adaption

·         Go to  Kanaal: Start_stop_voltage_limit

·         change to  12.1V ( standaard is 7.6V)

 

The Start-Stop will show as disabled because the energy requirement from the car is too high, which is not an error but a valid reason for SS to be disabled."

 

VCDS is a tad pricey for the odd change (£200-£300), making the more user-friendly and lower upfront purchase price of OBDeleven quite appealing...

 

 

 

 

 

 

 

Edited 3 September, 2018 by silver1011

[Tech1e]

I'm guessing its been implemented after the dieselgate hassles etc.

[MrTrilby]

6 hours ago, silver1011 said:

 

Some cars with stop/start don't benefit from upgraded batteries, alternators or starter motors, placing component longevity into question.

 

Cars with stop/start that aren't fitted with auxiliary oil pumps can suffer if the stop/start system turns the engine off after the turbo has been worked very heard, instantly stopping the cooling.

 

Cars without electric power steering can suffer increased steering effort if the engine stops too early and the power steering pump stops.

 

Interior heating and cooling is impacted when the engine is off. The car will turn itself back on when certain parameters aren't met i.e the selected interior temperature, but those parameters on some cars can be set too high which can have a noticeable impact on passenger comfort.

 

Headlights dimming, flickering or flashing each time the load on the electrical system is increased to start the engine.

 

During the winter months stop/start can prevent the engine from ever reaching full operating temperatures, meaning engine wear is potentially exacerbated.

 

 

I get why you might be concerned if they affected your car, but they don’t affect the Kodiaq do they? If the headlights flicker or dim on yours when the engine starts you need to pop it back to the dealer to get fixed. 

[Ootohere]

I would rather have a TDI with SCR sitting ticking over in front of me and around me in gridlock traffic rather than a 1.4 TSI / TFSI be it warmed up or coolant at 90*oC and oil not yet at that. 

At least the new engines coming will have a GPF. but still likely have the Emissions Controls inhibited at low ambient temperatures like Winter Commutes in the UK.

All those vehicles that got lower EU Test figures with low Co2 g/km and lower VED because they had Stop / Start which is more often inhibited / disabled in low temperatures and yet when even in for a UK MOT they are tested with at 'Operating Temperature' engines.

[silver1011]

2 hours ago, MrTrilby said:

 

I get why you might be concerned if they affected your car, but they don’t affect the Kodiaq do they? If the headlights flicker or dim on yours when the engine starts you need to pop it back to the dealer to get fixed. 

 

That's why I used the word 'car's' rather than 'Kodiaq'.

 

There are plenty of threads on here complaining about the stop/start system, especially on DSG equipped cars.

 

My Kodiaq has LED headlights with a relatively low power draw, but those with halogen headlights will dim whilst the engine starts.

 

You'd get some funny looks if you took it back to the dealer to complain.

 

[MrTrilby]

I thought this thread was about stop/start on the Kodiaq, not why you might want to disable it on some other hypothetical car?

[silver1011]

It is, and some of the issues I highlighted are associated with the Kodiaq, including the one about the headlights that you specifically mentioned.

[05surveyor]

19 hours ago, silver1011 said:

 

There appears to be quite some variation across different models, engines, fuel types and gearbox variants in how the stop/start system reacts.

 

Stopping too early, not starting quick enough, stopping just as you want to accelerate, jerkiness etc.

 

Some cars with stop/start don't benefit from upgraded batteries, alternators or starter motors, placing component longevity into question.

 

Cars with stop/start that aren't fitted with auxiliary oil pumps can suffer if the stop/start system turns the engine off after the turbo has been worked very heard, instantly stopping the cooling.

 

Cars without electric power steering can suffer increased steering effort if the engine stops too early and the power steering pump stops.

 

Interior heating and cooling is impacted when the engine is off. The car will turn itself back on when certain parameters aren't met i.e the selected interior temperature, but those parameters on some cars can be set too high which can have a noticeable impact on passenger comfort.

 

Headlights dimming, flickering or flashing each time the load on the electrical system is increased to start the engine.

 

During the winter months stop/start can prevent the engine from ever reaching full operating temperatures, meaning engine wear is potentially exacerbated.

 

In all these examples the system is working correctly, or as the manufacturer intends, but may result in driver dissatisfaction or reduced long-term reliability.

 

Each to their own, sometimes if I'm in heavy traffic I'll leave it on, but most of the time the minimal fuel savings aren't sufficient to offset some or all of the potential issues identified above. In those situations where I have reason to think that my engine noise or exhaust emissions are adversely impacting others I simply turn stop/start back on.

 

 

Thank you for that most comprehensive reply.  I've never noticed any of those on my Bear, and if I had noticed them I doubt it would trouble me.  I will keep my Stop/Start activated and forget all about this topic!

[Kenny R]

Let’s just put it down to those that just use a car as a tool and have no mechanical sympathy whatsoever and are quite happy to use stop/start even though it’s benefits are minimal, and those that have some interest in cars and how they work and prefer to turn stop/start off.

[Yogi-Bear]

35 minutes ago, Kenny R said:

Let’s just put it down to those that just use a car as a tool and have no mechanical sympathy whatsoever and are quite happy to use stop/start even though it’s benefits are minimal, and those that have some interest in cars and how they work and prefer to turn stop/start off.

 

What about those who have some interest in cars, know how they work, yet still use them as a tool and want to use start/stop even though the benefits might not be all that great to me as an individual.

 

Besides, the benefits to me as a driver might not be that great. The benefits to the cyclist filtering through a traffic jam or the pedestrian on the pavement, however, would be absolutely massive if every car sat still in that traffic jam (or at the set of lights) had its engine not running when it was stationary. Thinking of it as a system that is designed to benefit you, the driver, is wrong - and therein lies the problem. Marketing start/stop as a fuel-saving thing makes drivers think it is doing them good, and so they accept it. Marketing it as something which will actually benefit people outside their car most would turn drivers off, because they don't tend to care so much about the people not in their car. It's just the way we are as a species, unfortunately.

[MrTrilby]

49 minutes ago, Kenny R said:

Let’s just put it down to those that just use a car as a tool and have no mechanical sympathy whatsoever and are quite happy to use stop/start even though it’s benefits are minimal, and those that have some interest in cars and how they work and prefer to turn stop/start off.

 

What a ridiculous, ignorant and divisive thing to say. I’m out. 

[silver1011]

The stop/start feature affects the Kodiaq in different ways depending on its configuration, making our own personal experiences of it very different.

 

There are clearly arguments for and against, which might support why most manufacturers currently offer the driver the ability to turn this feature on or off.

 

It shouldn't come as a surprise, nor should we take offence, when one of us offers an alternative view?

[TonisT]

Not related to Kodiaq but my octy 3 1,4 manual behaves quite well with start/stop. I actually  do not mind it at all. Engine starts when I am pressing clutch pedal and starts on down stroke. So when I'm taking off, it's seamless.

Will have to see how it behaves when winter comes and we will go to freezing temps.

[Ootohere]

^^^ Likely it will behave as the engineers designed it.  It will not operate if the ambient temp is low enough, the cabin settings for temp are 16*oC or so different from the actual temp, 

the lights, radio, heated rear screen, heated mirror etc are on and the load on the battery is too high.

On occasions you will wonder what is up with it as it should be an active Stop / Start system, and on other times there will be no rhyme or reason to what is going on with it.

[silver1011]

The majority of complaints seem to come on cars with DSG. With a manual gearbox the stop/start is easy to manage or override by depressing the clutch. This is less easy with DSG combined with the fact that it would appear the activation of the stop start feature can also be manipulated by brake pedal pressure. This might explain why individual driving styles could see different results, positive and negative.

 

There have also been reports of the DSG box not engaging fast enough after the engine restarts causing a delay in moving forward, and / or resulting in the car jerking, especially if the driver is caught unaware. Again this is something that will likely be affected by individual driving styles, and no doubt something that improves as the driver gets acustomised with the cars habits.

 

This is quite an old list and has no doubt grown in the last year or two, but does offer a useful insight into some of the complexities of the stop start system...

 

 

Conditions for the automatic engine shut down (stop phase):

 

› The gearshift lever is in Neutral.

 

› The clutch pedal is not depressed.

 

› The driver has fastened the seat belt.

 

› The driver's door is closed.

 

› The bonnet is closed.

 

› The vehicle is at a standstill.

 

› The engine is at operating temperature.

 

› The charge state of the vehicle battery is sufficient.

 

› The stationary vehicle is not on a steep slope or a steep downhill section.

 

› The engine speed is less than 1200 1/min.

 

› The temperature of the vehicle battery is not too low or too high.

 

› There is sufficient pressure in the braking system.

 

› The difference between the outdoor- and the set temperature in the interior is not too great.

 

› The vehicle speed since the last time the engine was switched off was greater than 3 km/h.

 

› The front wheels are not turned excessively (the steering angle is less than 3/4 of a steering wheel revolution).

 

 

Conditions for an automatic restart (start phase):

 

› The clutch is depressed.

 

› The max./min. temperature is set.

 

› The Defrost function for the windshield is switched on.

 

› A high blower stage has been selected.

 

› The START STOP button is pressed.

 

 

Conditions for an automatic restart without driver intervention:

 

› The vehicle moves at a speed of more than 3 km/h.

 

› The difference between the outdoor- and the set temperature in the interior is too great.

 

› The charge state of the vehicle battery is not sufficient.

 

› There is insufficient pressure in the braking system.

 

[Phil-E]

Stop/Start works flawlessly and completely smoothly on cars equipped with a standard automation transmission.

 

I've driven a Touareg 3.0 TDI with 8 speed auto.

 

I think the "slack" in the drivetrain (torque converter) smooths everything out while the engine kicks in and the gear engages.

 

I've been a passenger in a DSG car with start stop and noticed a lag and jerkyness when trying to set off quickly.

[SuperbTWM]

On 03/09/2018 at 08:48, 05surveyor said:

 

I really don't understand why people object to Start/Stop if it is working correctly.  Just what is the problem?

 

For anybody who is mechanically sympathetic like myself do not like:

 

1/Putting a load on an engine that has just started to build up oil pressure

2/Having a stinking hot turbo with no coolant going through it

 

I appreciate in the real world it probably makes little difference to the longevity of an engine, but its just my preference. As mentioned above, it was only invented to play the emissions game on the EU drive cycle (which is nothing like real life driving)

 

I find in traffic where cars are edging forward all the time you end up with the engine doing lots of starting and stopping with next to no time actually 'off' to get any sort of reduction in emissions or fuel. I do sometimes use it when I know i'm going to be stopped for a minute or 2 but that's about it.

 

 

 

 

Edited 4 September, 2018 by SuperbTWM

[Ootohere]

Stop / Start is flawless on every DSG vehicle i have ever driven when it is functioning.  (Other than ones with faults, like DQ200's that are gubbed.)

I have been in cars that drive with flawless stop / start that drivers seem to be able to make a right mess of getting away from a stand still with, 

but they can be like that even if the car was running at a halt and the engine not stopped.

[BoxerBoy]

23 hours ago, MrTrilby said:

 

What a ridiculous, ignorant and divisive thing to say. I’m out. 

It's clearly a divisive topic, but I don't think the comment is either "ridiculous" or "ignorant".

 

Step aside and leave us to it by all means.

 

[robk999]

I must admit I was surprised this morning when the engine stopped as I was waiting to pull out of my drive!  The car must have been running no longer than a couple of minutes. 

[Ootohere]

^^^?

Why surprised if Stop / Start was enabled, the battery was full, there was not too much draw on power, the A/C was not on when the ambient temp was not right.

Stop / Start is there to stop the cars engine as you stop.....

 

More annoying is when enabled and they do not stop/start like the smaller cars and some big ones with stupidly small batteries.  eg Fabia's.

[robk999]

Because in previous cars it has never activated until the engine was warmed up.  At least, that's what I assumed was happening as it took around 10 minutes of driving before it would operate.

[Ootohere]

Vorsprung Durch Technik.   It was time that VW Group sorted out the systems that might have got Implausible / Irregular EU Emission Test results with Stop / Start systems that were more often 'inhibited' than 'enabled and activating'.

 

At least if you pull off and within a few hundred yards at the first busy junction the engine stops you are reminded that you might want to switch Stop / Start off until you are started on your trip, the coolant and oil is at efficient operating temperature and then you can enable again if it suits your location / commute / journey.

(i just turn the heater higher or hit the A/C button in some vehicles rather than try to see where Stop / Start Off buttons are. in some vehicles i am not familiar with and just using that trip.)

 

With me from leaving my door to the T junction is is 60 feet before the newest Stop / Start systems stop the car.

Well it has been until this first below 4*oC temps in the past week.

Edited 5 September, 2018 by Offski

[silver1011]

One of the prerequisites for the operation of the stop phase was that the engine is up to operating temperature...

 

 

I can confirm that on my previous 2016 Octavia (TDI 150PS non-SCR) and current (2018) Kodiaq, that this is now not the case.

 

As with everything, technology progresses I guess.

 

I was on the understanding that Skoda always recommended setting off from a cold start straight away, rather than letting the car idle (i.e. when defrosting etc.), in an effort to minimise engine wear. This is down to the fact that driving the car got the engine up to temperature quicker than if it was stationary / ticking over. I think it is widely acknowledged that the greatest amount of engine wear occurs during the early stages of a cold start.

 

It might be considered that having the stop start operate prior to the engine reaching operating temperature could exacerbate engine wear by delaying the engine warm up process.

 

Of course there are other elements affecting the stop start. If it is cold enough for the additional engine wear then it is also likely the driver will be calling for heat via the Climatronic system, which would prevent the stop start from activating until the engine is able to produce enough heat to satisfy demand, thus minimises engine wear.

 

It's all pretty complicated, and the obvious preference would be to simply let the car do its thing.

 

However, what the recent dieselgate scandal (EA189 Emissions Fix) has taught me is that Skoda (VAG) put meeting emissions targets well ahead of engine or component longevity (and some might argue rightly so), and therefore potentially reliability.

 

I like the fact that the stop start feature is switchable, allowing me to determine when it operates based on my preference for preserving the mechanical elements of my car versus my consideration for the environment and the health of myself and those around my car.