Stop start and braking

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monkeyhanger
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Re: Stop start and braking

Post by monkeyhanger »

That's the way stop-start with DSG is designed, like it or not. Add in the annoyance of stop-srart firing up the engine when the car in front has shuffled forward a foot while a traffic light is still red (thanks to the ACC system).

I switch stop start off every journey and only put it on when I know I'm in for a long wait e.g. roadworks.

With the battery drain the dashcam has in parking monitoring, the car rarely has the spare battery capacity to support stop start anyway.

Stop start works far better on a manual car where clutch pedal use governs stop start activation so you can anticipate a light change, have the engine fire up prior to the light change and only move off when you put the car into gear.

ACC works best with DSG, Stop Start works best with a manual box.
SRGTD
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Re: Stop start and braking

Post by SRGTD »

Andy Beats wrote: Tue Oct 20, 2020 8:47 am With regard to LED brake lights, the 'light technology' may well not result in dazzling as much as traditional bulbs on a 'bulb v bulb' basis, but manufacturers have more than made up for that by making ridiculously large brake lights.
Some cars have them run the full width of the tailgate, it's ridiculous and I get dazzled more by brake lights than ever before.
Audi is one car manufacturer that seems to have an obsession with illuminating the entire width of some of their cars. IMO you wouldn’t want to be sitting behind an A8 at night for very long with the driver applying the brakes (check out the YouTube video at around 2min 10sec to 2min 20sec). Audi’s A7 is pretty much the same, and there are probably other Audi models with similar rear end light shows.

https://www.youtube.com/watch?v=7slec58xdj4
Andy Beats
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Re: Stop start and braking

Post by Andy Beats »

SRGTD wrote: Tue Oct 20, 2020 10:00 am
Audi is one car manufacturer that seems to have an obsession with illuminating the entire width of some of their cars. IMO you wouldn’t want to be sitting behind an A8 at night for very long with the driver applying the brakes (check out the YouTube video at around 2min 10sec to 2min 20sec). Audi’s A7 is pretty much the same, and there are probably other Audi models with similar rear end light shows.

https://www.youtube.com/watch?v=7slec58xdj4
They also do those 'sweeping' indicators.
They almost make me physically ill, they're such a pile of wa....
SRGTD
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Re: Stop start and braking

Post by SRGTD »

Andy Beats wrote: Tue Oct 20, 2020 10:45 am
SRGTD wrote: Tue Oct 20, 2020 10:00 am
Audi is one car manufacturer that seems to have an obsession with illuminating the entire width of some of their cars. IMO you wouldn’t want to be sitting behind an A8 at night for very long with the driver applying the brakes (check out the YouTube video at around 2min 10sec to 2min 20sec). Audi’s A7 is pretty much the same, and there are probably other Audi models with similar rear end light shows.

https://www.youtube.com/watch?v=7slec58xdj4
They also do those 'sweeping' indicators.
They almost make me physically ill, they're such a pile of wa....
Taking form over function a step too far IMO.
vc-10
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Re: Stop start and braking

Post by vc-10 »

monkeyhanger wrote: Tue Oct 20, 2020 9:35 amAdd in the annoyance of stop-srart firing up the engine when the car in front has shuffled forward a foot while a traffic light is still red (thanks to the ACC system).
This is the most annoying thing ever. I wish there was a way to turn it off. I don't see why they implemented it- it gets confused so often and kicks the engine back on for no reason. The most annoying thing is that the system on my Ibiza can 'see' the car in front of the car in front. Quite often at city traffic lights that car is able to go but the car in front of you isn't. So it kicks the engine back. Infuriating.
Nodster
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Re: Stop start and braking

Post by Nodster »

ryanponti wrote: Mon Oct 19, 2020 9:16 am
Nodster wrote: Sun Oct 18, 2020 1:20 pm
PO10ASH wrote: Sat Oct 17, 2020 9:03 pm Anyhow, I've found myself starting to put my car into N and then keeping my foot on the brake, but only when sat for awhile.
I don't think you need to do that, if you're keeping your foot on the brake just keep it in D. The clutch will be disengaged automatically so there's no wear to worry about by sitting stationary whilst in D. :) Saves you having to keep going from N > D. Fair enough if you wanted to apply the handbrake and lift off the brake.
I thought that this would be the case but the car does feel like its still trying to pull away even with the brake pressed hard hinting towards slight friction on the clutch. I put the active sport display on and if you leave the car in neutral the boost gauge shows 0.26-0.28 bar, if its in D its usually 0.34-0.38. I have sat there before and just switched between the two and you can see the change in boost.

I thought maybe by shifting into D the car thinks we are going to move so has prepared to set off so i came to stop whilst in D and it stayed in the 0.34-0.38 range then knocked it into N and it dropped back to 0.26-0.28. I know this isn't exactly a large increase in boost 1.7 PSI ish but it indicates to me that there is something causing the car to produce extra boost and my conclusion was extra friction in the drive-train as that is the only thing that is changing.
I wonder if the slight boost increase from "N" to "D" is perhaps as you say, preparing to move, but also for hill assist. So that extra boost is what helps hold / crawl? Dunno... just spit balling now. :)
silversurfer2020
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Re: Stop start and braking

Post by silversurfer2020 »

Having read through this thread I am surprised that no-one has mentioned the health benefits. The stop start system operates most of the times in cities and towns which also have a high residential occupation. A lot of these residents are pedestrians who are often children. We should not be thinking selfishly as to what is best for our convenience. The court case today about a 9 year old girl with asthma cause of death due to traffic pollution should make us all think. I always leave the stop start system on when I drive our Polo: I only turn it off briefly at one busy roundabout and one T-junction when I know I often need to pull off in a hurry. So the next time you sit in traffic with your engine running perhaps just think about who's life you may be shortening.
john M
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Re: Stop start and braking

Post by john M »

I have no problem with the concept but what I find utterly inexplicable is that it operates with a stone cold engine once you have travelled 0.5kms, I would think that the extra fuel consumed in this cold state actually increases pollution.
I don't arm mine until the coolant gauge is ~ 70C.
Andy Beats
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Re: Stop start and braking

Post by Andy Beats »

silversurfer2020 wrote: Wed Dec 16, 2020 2:04 pm Having read through this thread I am surprised that no-one has mentioned the health benefits. The stop start system operates most of the times in cities and towns which also have a high residential occupation. A lot of these residents are pedestrians who are often children. We should not be thinking selfishly as to what is best for our convenience. The court case today about a 9 year old girl with asthma cause of death due to traffic pollution should make us all think. I always leave the stop start system on when I drive our Polo: I only turn it off briefly at one busy roundabout and one T-junction when I know I often need to pull off in a hurry. So the next time you sit in traffic with your engine running perhaps just think about who's life you may be shortening.
I hardly ever do any town driving in mine.
TBH, if I was, I'd be a special kind of idiot buying a GTi....
Stuart_Rendall
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Re: Stop start and braking

Post by Stuart_Rendall »

john M wrote: Wed Dec 16, 2020 2:52 pm I have no problem with the concept but what I find utterly inexplicable is that it operates with a stone cold engine once you have travelled 0.5kms, I would think that the extra fuel consumed in this cold state actually increases pollution.
I don't arm mine until the coolant gauge is ~ 70C.
The catalytic converter doesn't really do much at low temps also so on cold days where the engine and exhaust hasn't heated up the pollutants will be much higher than normal.
roywolfey
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Re: Stop start and braking

Post by roywolfey »

GTI Polo Fin wrote: Sun Oct 18, 2020 7:32 pm
Magpie-01 wrote: Sat Oct 17, 2020 5:52 pm I have heard of a few people who put the car into neutral and put hand brake on
Those few people are stupid
I personally follow the Highway code. :wink: Lighting requirements 114 "In stationary queues of traffic, drivers should apply the parking brake and, once the following traffic has stopped, take their foot off the footbrake to deactivate the vehicle brake lights. This will minimise glare to road users behind until the traffic moves again."
tom.wright
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Re: Stop start and braking

Post by tom.wright »

I also feel (perhaps I'm wrong) that having the engine stop and restart umpteen times as I inch forward in a queue of traffic a few yards at a time is probably doing more harm than good to the starter motor and battery than the negligible reduction in emissions that it's making by having the engine stopped for 10 seconds at a time. If I'm going to be stationary for more than a minute or so then fair enough, but the stop start system we have is far too aggressive with very little gain. I'm sure VW love it as they probably replace a lot more batteries and starter motors post warranty because of it.
silversurfer2020
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Re: Stop start and braking

Post by silversurfer2020 »

There is nothing to gain in inching forward a few yards at a time, in fact you are going to get more exhaust fumes from the car in front. Wait until a 10 yard gap opens up and then pull forward and then stop and your engine also stops. Repeat this until the end of the traffic jam.
monkeyhanger
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Re: Stop start and braking

Post by monkeyhanger »

silversurfer2020 wrote: Wed Dec 16, 2020 8:07 pm There is nothing to gain in inching forward a few yards at a time, in fact you are going to get more exhaust fumes from the car in front. Wait until a 10 yard gap opens up and then pull forward and then stop and your engine also stops. Repeat this until the end of the traffic jam.
You've no choice if you have ACC and the sensor decides the cars in front are moving so it starts the car back up in readiness to move. Might as well kill the stop start and leave the engine on in that situation.
silversurfer2020
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Re: Stop start and braking

Post by silversurfer2020 »

I wouldn't think that ACC is an accessory that many people pay for?
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