Start/stop good or bad, worth it or not?

[Dogpatch]

Hello,

 

As we all know, start/stop can be deactivated and de-coded.

But how good or bad is this function really?

 

Let's say you save fuel, that's a good thing ofc. But is that small saving worth it on the engine?

I'm thinking startermotor, bearings and other things that may get a shorter life because of all the starts.

Also, let's say you're driving like a maniac and then just stop at a red light and the engine shuts off. Then the turbo will not get any oil which will in the long run kill the turbo.

 

Let's brainstorm this and see what people think. Is it really worth the small saving in fuel?

[cnc]

I cannot recall anyone on this forum needing a new starter motor or any other related item that the stop/start could have any effect on - they are built for it. Personally I've had three cars now with stop/start and never had any trouble with any of them, all three have done more than 100k, one did 146k.

Apart from the potential fuel saving there's also the emissions especially in cities so it can affect peoples health as well as the noise of the engine running when it doesn't need to.

A few years ago when I had my first stop/start I wasn't sure about it, now I just let it do its job without even thinking about it.

[FelisBengalensis]

I think the only annoyance I have with the version in the S3 is that it stops the engine whilst the car is still in motion, and that shuts off the electric power steering assist. It also has a nasty habit of cutting out at innoppotune moments and can catch one out at junctions or roundabouts when you get a chance to nip out inky to find the engine has cut and in the few seconds it takes to restart and engage the DSG system, the chance has gone.

I have not had mine disabled, but have learned to turn it off at every junction or roundabout which sort of jakes it pointless about 80% of the time I am driving. In traffic I can see the advantages however the poor fuel economy of the 190DSG is not going to be improved by a Stop/Start system - nor has it been.

I'm not certain of the fuelling on the diesels but I would expect a longer 'starting pulse' from the injectors which could mean that for short stops there is no advantage economy wise.

As for wear on the starters etc, mine will be gone before the warranty runs out, so not my concern. From an engineers viewpoint it has to increase wear and shorten component life. This may not happen during what manufacturers determine as the service life of a vehicle - often no more than the warranty period.

[Dogpatch]

I think the only annoyance I have with the version in the S3 is that it stops the engine whilst the car is still in motion, and that shuts off the electric power steering assist. It also has a nasty habit of cutting out at innoppotune moments and can catch one out at junctions or roundabouts when you get a chance to nip out inky to find the engine has cut and in the few seconds it takes to restart and engage the DSG system, the chance has gone.

I have not had mine disabled, but have learned to turn it off at every junction or roundabout which sort of jakes it pointless about 80% of the time I am driving. In traffic I can see the advantages however the poor fuel economy of the 190DSG is not going to be improved by a Stop/Start system - nor has it been.

I'm not certain of the fuelling on the diesels but I would expect a longer 'starting pulse' from the injectors which could mean that for short stops there is no advantage economy wise.

As for wear on the starters etc, mine will be gone before the warranty runs out, so not my concern. From an engineers viewpoint it has to increase wear and shorten component life. This may not happen during what manufacturers determine as the service life of a vehicle - often no more than the warranty period.

 

 

Interesting fact.

I've had my Superb 280 for 6 days now, and I've also noticed it shuthing of when in motion. I plan to disable the system as I will most of the time drive the car quite hard. I dont want the engine to cut of the oil to the turbo after I've been having fun.

[cnc]

I dont want the engine to cut of the oil to the turbo after I've been having fun.

micloi also has a 280 and says he can hear the pump still going after the engine has stopped so it shouldn't be a problem.

 

Post #14 here http://www.briskoda.net/forums/topic/397243-normal-oil-temperature/?hl=%2B280+%2Bturbo+%2Bpump#entry4683453

[Dogpatch]

micloi also has a 280 and says he can hear the pump still going after the engine has stopped so it shouldn't be a problem.

 

Post #14 here http://www.briskoda.net/forums/topic/397243-normal-oil-temperature/?hl=%2B280+%2Bturbo+%2Bpump#entry4683453

 

Interesting. I'm gonna try to listen for this on mine!

[Csory]

Mine is a TSI 220 with S/S active and can't complain. First I was afraid, ("I was petrified  :D " - sorry, couldn't resist ) but the petrol engine starts up in an instant - as soon as I ease my foot off the brake pedal (practically, as I just start to ease my foot...) it is up and running. And yes, I can hear the pump running while the engine is off - just hope that it is the oil pump and not the steering servo  :D

Edited 12 January, 2017 by Csory

[Croat]

I just paid 200 quid for new battery for damn SS function. If you ask me I am not sure if it saved enough fuel to justify the cost!

[skidpan]

Had stop/start on 4 cars already, when the Superb arrives it will be the 5th.

 

Not had any issues with the systems or starter motors but one did have to have a faulty battery replaced under warranty. In truth I had not spotted a problem, dealer picked it up in the diagnostics and suggested it needed a new battery which would be FOC if I wanted one. You would have been mad not to take up his kind offer when the car was almost 3 years old.

 

In slow moving queues we generally switch it off but the rest of the time we just let it do its thing.

 

In the Leon it does not function after a swift motorway drive at the junction traffic lights. Its not the battery voltage, its the oil temp that's too high, drive for another 200 yards to the next lights, temp drops, stop/start works. Just as VAG intends it to work.

 

As for fuel savings probably about a mug full over 12 years.

 

But I recon its saved me over £1000 in VED during the same period compared to earlier identical cars without stop/start.

 

So whats not to like.

 

 

 And yes, I can hear the pump running while the engine is off - just hope that it is the oil pump and not the steering servo   :D

 

 

It won't be the oil pump, its engine driven and not electric. Could be any electric device making a noise. 

Edited 12 January, 2017 by skidpan

[Rainmaker]

The noise you can hear is the electric water pump, designed to keep on cooling the turbo when the engine is switched off. The problem traditionally with turbos was the engine suddenly cutting off while the turbo was still cherry red hot, and the oil in the turbo's pipes burning off and solidifying. That led to blocked oil pathways and coking, up until... boom. The pump on the S3 cools down the turbo gradually regardless of whether the engine is on or off, so there's nothing to worry about on that score. Drive hard all you like.

 

 

Edited to fix the typos, courtesy of my six month old who is trying to 'help' inform you all of her latest news from the comfort of my lap. :D

Edited 12 January, 2017 by Rainmaker

[GaSelle]

It would so much like to disable the function; it doesn´t work very well with DSG. When the light changes to green and you push the accellerator down slightly, the car starts instantly. But sometimes it releases the clutch a little to fast, so the car "jumps" forward. A fast bling on the accellerator, the car starts, and then you can drive off.

I tried to decode it with VCDS, and it did work - but my OCD can´t handle the fault, the coding gives. (@ symbol with a line over it at all times in the MaxiDOT, and a "Start/stop" related fault in the Car menu on the radio). So i re-activated it, and has learned to live with it - sort off. You can avoid it shuts off the engine, by only gently pressing the brake pedal.

[Csory]

GaSelle: do you have "auto hold" enabled? I have disabled mine so that I have to keep the brake pedal depressed to avoid crawl - greatly helps with the s/s as  the engine is already up and running by the time I put my foot on the accelerator. (With auto hold I would not have to keep the brake pedal depressed, hence the first clue to the motor management to fire up the engine would be my foot on the gas pedal - too late for a smooth start. Now it just jumps back to life as soon as I ease my foot off the brake.)

[IanJD]

GaSelle: do you have "auto hold" enabled? I have disabled mine so that I have to keep the brake pedal depressed to avoid crawl - greatly helps with the s/s as  the engine is already up and running by the time I put my foot on the accelerator. (With auto hold I would not have to keep the brake pedal depressed, hence the first clue to the motor management to fire up the engine would be my foot on the gas pedal - too late for a smooth start. Now it just jumps back to life as soon as I ease my foot off the brake.)

Same for me -- "auto hold" seems pretty pointless with a DSG given that even without it you have hill hold, and starts are much quicker and smoother without it.

 

Also SS only kicks in with heavier pressure on the brake pedal -- if you come to a stop under light braking and keep your foot lightly on the brake nothing happens, if you press the brake a bit more heavily then SS happens.

 

I've never had the slightest problem with DSG+SS (auto hold off) being slow or jerky when starting off.

[Warrior193]

Interesting fact.

I've had my Superb 280 for 6 days now, and I've also noticed it shuthing of when in motion. I plan to disable the system as I will most of the time drive the car quite hard. I dont want the engine to cut of the oil to the turbo after I've been having fun.

The stop-start should not activate when the vehicle is rolling at more than 1 or 2 MPH, it is also disabled (not active) while you are moving the steering wheel, these are just two of the many things that SHOULD prevent the engine from stopping. If owners are having their engines stop while the car is still rolling, they should get their dealer to check it.

[Dogpatch]

Interesting answers.

I hope the de-coding of Start/Stop will work for me. As I dont see the point in it. The auto hold works great, I dont need to hold the brake pedal down.

But I always put the car in N when at a light. I dont like it trying to "get away". That only eats the clutch pre-mature.

[NX01]

Always disable start/stop when I get in.  Never had it before, so nothing to miss.  I occasionally use it if stopped at a level crossing or something similar when I know I am going to be sat a few minutes but then it is done manually as an off / instant on.

 

Autohold is also permanently off, one joy of an automatic is it being able to move and creep itself without accelerator.  Great for those close parks and also traffic queues.

[micloi]

It would so much like to disable the function; it doesn´t work very well with DSG. When the light changes to green and you push the accellerator down slightly, the car starts instantly. But sometimes it releases the clutch a little to fast, so the car "jumps" forward. A fast bling on the accellerator, the car starts, and then you can drive off.

I tried to decode it with VCDS, and it did work - but my OCD can´t handle the fault, the coding gives. (@ symbol with a line over it at all times in the MaxiDOT, and a "Start/stop" related fault in the Car menu on the radio). So i re-activated it, and has learned to live with it - sort off. You can avoid it shuts off the engine, by only gently pressing the brake pedal.

 

If you use VCDS to just increase the minimum voltage needed for start stop to be activated, this should not give a fault? Or this is what you did and still got the fault in the menu?

[nicknorman]

With autohold and start/stop active, I find a slight tap on the throttle starts the engine but keeps the brake on, a second tap releases the brake for a smooth moving off in slow traffic.

But yes I too suffer from the engine stopping just before the car comes to a halt - which is annoying if you don't actually intend to come to a halt. It only does it occasionally though, usually on the first auto-stop after a long period of driving. I'm just learning to routinely select it off, and only select it on when I can see I'm going to be stationary for a while e.g. traffic lights just gone red

Edited 12 January, 2017 by nicknorman

[Prykey]

I don't have any problems with mine, I just turn it off after I have started the car :D

Edited 12 January, 2017 by Prykey