Start/Stop

[Colin P]

So I was wondering views on this one. I’ve always taken the view that I’d rather use a bit more fuel than add the wear on to the flywheel, starter and battery. It seems a false economy to me. Usually I’d de spec Start/stop but on the last 2 cars it’s not possible. One you can turn off permanently, the other, my new daily you have to turn off every time you get in the car as it’s irritating. Was wondering what others views were.

[Spinney]

I've got it on my Merc and, to be honest, it's never been a problem for me to just let it do its thing. It always defaults to active when I turn the ignition on and I can't really see the point in turning it off anyway since the engine always starts immediately as soon as I come off the brake or touch the throttle pedal. It used to take me a bit by surprise on the first car I had with it fitted, every time it cut the engine, but I quickly became used to it.

I understand the concerns about additional wear on some parts but they have been engineered to cope with that potential extra wear, so not really a concern for me.

[mik]

It doesn’t wear your flywheel ring-gear or starter motor as cara with stop-start have different alternators to work as the motor to start the engine.

wife’s f-pace has the system, and whilst I don’t love it, I can’t deny it works very well. In the time it takes my foot to leave the brake and depress the throttle it has started. No biggy.

[C8RKH]

But you shouldn't really be stopped with your foot on the brake. That's what the handbrake is for if we're sticking to the rules surely.

[Spinney]

11 minutes ago, C8RKH said:

But you shouldn't really be stopped with your foot on the brake. That's what the handbrake is for if we're sticking to the rules surely.

I take it you’ve not tried the parking brake on a Mercedes then? They are comically poor at holding the car on anything other than a completely flat surface. If I’m going to be stopped for anything more than a few seconds, I normally slip out of drive into neutral and use the brake hold as the parking brake is so awful. 

20 minutes ago, mik said:

It doesn’t wear your flywheel ring-gear or starter motor as cara with stop-start have different alternators to work as the motor to start the engine.

wife’s f-pace has the system, and whilst I don’t love it, I can’t deny it works very well. In the time it takes my foot to leave the brake and depress the throttle it has started. No biggy.

My car definitely starts on the normal starter motor. I don’t have any experience of JLR cars though. 

[Colin P]

40 minutes ago, C8RKH said:

But you shouldn't really be stopped with your foot on the brake. That's what the handbrake is for if we're sticking to the rules surely.

Nope, they are parking brakes. Had this conversation with little brother who was a driving examiner around the Mercedes foot brakes and electric handbrakes. 

Using the foot brake is only an issue if the discs/pads are properly hot. 

46 minutes ago, mik said:

It doesn’t wear your flywheel ring-gear or starter motor as cara with stop-start have different alternators to work as the motor to start the engine.

Both ours are the starter motor, you can hear it. Also heard it on a Merc today, as it took half a second to restart.

[philcool]

Friends BMW 1series stop start with AGM battery needed a new battery ok not to had you think £120 but then it has to go to BMW to program the software to charge the battery correctly as its new and the stop start system will over charge the battery 

Total bill £463 So that's all the diesel saved gone in one battery change.

My view if your keeping the car don't bother with the stop start extra wear on the engine keep starting and stopping with zero oil pressure each time 😣

If your going to change it after 3 years no problem let someone else pick up the bill down the line 

Had a company vauxhall vivaro 2 Years or 25k oil changes great all the money saved soon evaporated when the turbo exploded  68k miles and when inspected oh yes poor lubrication guess what Vauxhall win again as the service costs every 2 years were the same as two yearly services anyway.

First service on a brand new diesel at 2 years and 22k miles shocking when you examined the oil on the Dip stick it had no lubricity left between your fingers.

 

[Spinney]

55 minutes ago, philcool said:

Friends BMW 1series stop start with AGM battery needed a new battery ok not to had you think £120 but then it has to go to BMW to program the software to charge the battery correctly as its new and the stop start system will over charge the battery 

Total bill £463 So that's all the diesel saved gone in one battery change.

My view if your keeping the car don't bother with the stop start extra wear on the engine keep starting and stopping with zero oil pressure each time 😣

If your going to change it after 3 years no problem let someone else pick up the bill down the line 

Had a company vauxhall vivaro 2 Years or 25k oil changes great all the money saved soon evaporated when the turbo exploded  68k miles and when inspected oh yes poor lubrication guess what Vauxhall win again as the service costs every 2 years were the same as two yearly services anyway.

First service on a brand new diesel at 2 years and 22k miles shocking when you examined the oil on the Dip stick it had no lubricity left between your fingers.

 

I’ve always felt the longest you should go between oil changes is 1 year at most, maybe less if doing a high mileage, regardless of manufacturers recommendation. The stop/start is more about reducing the emissions rather than saving fuel and mine doesn’t stop anyway until the engine is warm, so I don’t believe additional wear due to starting with zero oil pressure is really any problem. If you were continually starting a cold engine then may be but otherwise I don’t have any problem with it myself. 

My wife’s Merc with stop/start is 7 years old and still going strong on the original battery. In my view, additional wear and tear on cars so equipped, provided they’ve been properly designed for it, is really a non issue. 

[Escape]

Luckily I don't have start/stop on my own cars (they're all way too old 😎) but I am confronted with it if I drive another car or even as a passenger. I quite hate the system and always turn it off if I'm forced to drive a car so equipped. I'm convinced the real world savings are negligible, but it will surely help do better on some tests. 

I too have heard several stories of early failures of alternators and such. Not all cars have redesigned parts, some just add the start/stop to be able to claim lower emissions. As said probably not a problem for the first 3 years or so, and after that no one cares...

Filip   

[Colin P]

 

2 hours ago, Escape said:

just add the start/stop to be able to claim lower emissions.    

True, as a prime example of a waste of time, my wifes JCW has start stop  (2.0 Twin spool Turbo in a Mini and has to run on Super Unleaded) yet it has a start stop (permanently turned off) and "Green" mode (basically knocks 200bhp off and ruins the car) - never used and a whole programme which makes a fish in a bowl happy if you drive economically. 

If any of that was of interest she'd have had the Mini One!! I like to slosh the water so the fish gets thrown out of the bowl.

[Escape]

That reminds me of a friend who had a company Mini Cooper some years ago. It also featured start/stop. While he was telling me about the claimed fuel savings, the light turned green and he duly floored it to show how the saved fuel was put to good use. 😆

Filip

[Alfa2Evora]

14 hours ago, Colin P said:

............ as it took half a second to restart.

Round here, if you took that long to get moving on a green light you'd have been punted up the 'harris' by the guy behind (ooh, err, missus!). 😱

[electro_boy]

Always thought cars with stop start where engineered to cope with the extra wear and tear so it’s not an issue? Batteries and start motors etc are different to normal spec?  So for me I always keep it on.  Some systems are better than others but usually when the strat stop systems are in use is round town in traffic where I don’t care about having a 0.5 sec delay in the engine sparking up. 

[ramjet]

I was manually doing the start/stop thing in my Holden Rodeo. I have never worked out the cost of wear over time (starter, flywheel, battery) as I was not really sure how to about it versus fuel saving.

It wasn't until I watched a youtube video by John Cardogan (Aussie) that went into the start/stop technology and as far as Mazda was concerned, it was going to cost nearly $500 for a new battery that was built for the start/stop technology versus a standard battery.

He then was able to equate it back against fuel saving (Mazdas own figures) and worked out that your car would basically have to be switched off for at least 15 minutes every trip you made in the car for it to break even.

[LotusLeftLotusRight]

My first experiences with it on my VW Passat was how potentially dangerous it can be when approaching a roundabout and it cuts out just as you want to pull onto the roundabout itself. It even cuts out when approaching traffic lights etc and effectively kills the controls (PAS etc.). I have to remember to switch it off before every journey. It’s just a con for massaging laboratory/advertised MPG figures. Maybe relevant in a city centre, but not much else.

[Spinney]

I find some of the experiences on this thread all very strange and quite alarming. The system fitted to my car is really very benign and doesn't interfere in any way with how the car drives or behaves. Unlike the post before this, mine doesn't cut in until the car is completely stationary and I mean completely. If I'm just trickling along and barely moving, it won't cut in at all, so pulling out of junctions or at roundabouts are never an issue.

Further, I would measure the start time, upon taking my foot off the brake and onto the throttle in milliseconds, so there is really no discernible delay at all. Finally, having seen some of the quotes regarding replacement battery costs, out of interest I've just priced up a replacement for my car, not that it needs one, at only £140, which I don't honestly think is too horrendous.

I don't know, maybe Mercedes have engineered a better solution than other manufacturers??? Having said all of the above, I don't actually care whether my car has stop/start or not but it came as standard and has never caused me to think it is a poor or unresolved feature. It just does its thing without me ever really noticing.

[ramjet]

 

25 minutes ago, LotusLeftLotusRight said:

My first experiences with it on my VW Passat was how potentially dangerous it can be when approaching a roundabout and it cuts out just as you want to pull onto the roundabout itself. It even cuts out when approaching traffic lights etc and effectively kills the controls (PAS etc.). I have to remember to switch it off before every journey. It’s just a con for massaging laboratory/advertised MPG figures. Maybe relevant in a city centre, but not much else.

Wow. I have only ever had it come on when the car was stopped. I would have thought that there was definitely some sort of interlock that would read the car speed and only allow the engine to shut off when stopped?

[LotusLeftLotusRight]

You’d think so wouldn’t you, but no. It’s only walking pace, but still...

[ramjet]

Our new Skoda is definitely only at standstill. It sometimes restarts even if you just release some pressure on the brake pedal.

[mayevora]

I had it on last two cars for last 8 years and don’t even notice it anymore.

[Colin P]

57 minutes ago, LotusLeftLotusRight said:

You’d think so wouldn’t you, but no. It’s only walking pace, but still...

I’ve driven a few and never had this happen. I wonder if there is an issue.

Usually only stop when stationary, neutral and clutch up. Usually starts as the clutch is depressed to put in gear.

[Escape]

It really shouldn't kick in if the car isn't completely stationary, that's properly dangerous! 😲

As for city traffic, I'm typically surrounded by (company) cars with start/stop when coming home from work. Usually very busy traffic, and there constantly stopping and starting again to move a few meters. No way that do have any good! Sitting at a red light or such for half a minute or more is a different situation, where it's probably not a bad idea. Just like I know to switch of the engine myself when waiting for a railway crossing, as that can take up to 10 minutes.

Filip

[LotusLeftLotusRight]

It's an October 2017 (new shape) manual factory order Passat TDi that I have owned since new. It cuts out when going at very slow speed from second to neutral as I approach a junction/roundabout/traffic light, unless I keep the clutch pedal down. Sure you can keep the clutch pedal down and already stick it in first in readiness of setting off again, but that's not how I drive. I will only depress the clutch pedal and select first from neutral when I know I am about to move off.

I would be interested if any of you can replicate this. It's probably only a manual gearbox thing.

Try the following (where safe!) with stop/start feature functioning:

1) set off and drive at normal pace

2) start braking and go back down the gears in anticipation of stopping

3) when you are in second gear and have nearly stopped, depress the clutch and put the gearstick into neutral and then release the clutch pedal, whilst completing the braking procedure. At this moment my car's engine will switch off even before it has come to a halt. The brakes will still work and the car will stop, but the PAS stops and the steering wheel goes heavy until I press the clutch pedal again to engage first gear to set off again.

[Bibs]

I've never experienced that in my Scirocco. I'll try to replicate it but on the whole, like Ian, I barely notice it's there. It's always on in my car unless I'm in a nose-to-tail jam and moving a few yards many times which is the only circumstance I can think where I'll turn it off.

[Steve V8]

The system on the wife's BMW 2 series (auto) is dangerous, the issue happens when the battery has received enough charge to cut the engine at exactly the same time as you are about to pull away,  the delay is probably less than a second, but if you're pulling out onto a busy road into a gap in traffic, it takes less than a second for that gap to disappear.