Start stop - Actually worthwhile, or pointless eco gimmick?

[Kozy]

Seeing as my 'trusty' old MX5 is having starter motor issues at the moment, this got me thinking about all the cars now fitted with stop start rubbish. If my car had it, I'd be stranded every other time I came to a set of lights, I would hate it and probably seek to disable it.

To the people that have this in their cars, is it actually worthwhile or is it simply another means to falsify the official MPG and CO2 figures? Do you like it or rather it wasn't there?

I just can't see that it saves any worthwhile amount of fuel, considering the energy which must then be returned to the battery in the form of additional engine load from the alternator...

Can these systems be switched off/disabled fairly easily if they start becoming problematic?

[Rawwr]

I like it in my Fiesta. Works well. Unintrusive. No problem. Can't see why I'd deactivate it?

[Kozy]

Rawwr said:

I like it in my Fiesta. Works well. Unintrusive. No problem. Can't see why I'd deactivate it?

Further down the line, when the car gets older.

They don't start 'on the button' forever.

[Fastdruid]

Kozy said:

To the people that have this in their cars, is it actually worthwhile or is it simply another means to falsify the official MPG and CO2 figures?

It's to falsify the official MPG and CO2 figures. If you look at the test a large portion is spent stationary, if you can remove the idling then even a poor mpg car looks better.

Kozy said:

I just can't see that it saves any worthwhile amount of fuel, considering the energy which must then be returned to the battery in the form of additional engine load from the alternator...

Well they are beefed up and under the right circumstances it does save an appreciable amount. But it all depends on your driving. I for example rarely have any 'stopped' time on my commute but I do frequently have a lot of "drop to ~5mph and then back up to 50mph" sections. So I'd save almost nothing in comparison to for example someone who drove into a city centre and had to stop at every single traffic light with ~50% of the "journey" actually spent stationary.

Kozy said:

Can these systems be switched off/disabled fairly easily if they start becoming problematic?

Yes... and No. They can be turned off but it's a "per event" switch off, ie every time you get into the car you have to turn it off. This is because the mpg/CO2 tests are performed at the cars default settings. If you can change something permanently you can't use it for the tests. This is also why so many performance cars come with a 'sport' button so the economy is tuned for CO2/mpg in the default 'economy' mode and then all turned off by everyone every time they drive it (who then complain about having to turn on sport mode every time).

Edited by Fastdruid on Wednesday 23 July 16:04

[AC43]

I had it in a loaner E250 CDI.

It was the quietest chug-a-bug four pot I'd even driven. Well, until the damn engine clattered in to life each time the traffic moved sending shuddering juddering oscillations through the bodyshell.

Technically it worked very well. Shame it wasn't on a 6 pot diesel or, even better, a petrol.

Edited by AC43 on Wednesday 23 July 16:01

Edited by AC43 on Wednesday 23 July 16:03

[Motorrad]

Done before here but I think they're great in the city because it means I can thrash them off the line with ease even if the car is faster than mine.

[Chicane-UK]

Had it in a Fiat 500 that I owned for about a year. Worked really well and amusingly even works as an "anti-stall" system - sometimes I'd misjudge the power needed to pull away as it was a bit gutless, and cause a stall, and immediately the engine would restart itself as soon as you dipped the clutch again - neat.

From what I read it was supposed to generate fuel savings if you were going to be stationary any more than a few seconds so, gets a thumbs up from me.

[CrutyRammers]

I've just bought a car with this. While impressive, it's a bit annoying (though that's probably just me), and a couple of times I've gone to pull away too quickly for it - have to deliberately slow things down a touch. And while sometimes it seems sensible, when you're sat at the lights for a couple of minutes, in most instances I'm only there for 10-20 seconds and it seems like it's doing more harm than good. I'm sure it's been plenty tested, but I don't like the idea of constantly stopping and restarting engines from a wear point of view.
Fortunately you can turn it off.

[Far Cough]

If your commuter journey is from one side of London to the other during rush hour every day and then back again ( I pity you ) it may make a small difference but that will be off set once you have to replace the starter motor because its worn out.

[BritishRacinGrin]

I had the same scepticisms about battery and starter motor lifespan but these systems have been around for a while now and I haven't actually heard of any problems.

[trashbat]

If you live in a city or large town then it's probably worthwhile in terms of ambient noise and air pollution.

[GetCarter]

I have it in both my cars. There's a button to turn it off.

[Limpet]

I turn mine off. I have no problem with the concept, but BMW haven't worked out how to make a 4 cylinder diesel start without a jolt that thuds through the car, and knocks your hand off the gear lever if you're just resting it. It's horrible.

[djfaulkner]

It's ok....

I usually turn it off in stop/start traffic as it gets annoying.
and when stopped for a while in this warm weather, as when the engine is off so is the air con, so warm air get blown in.


I do have a question for other users.....
The system is design so when the clutch is pressed the engine starts.
So if you are stopped downwards on a hill and you let the car roll, before engaging the clutch and the engine starts.

Would this cause any issues.

I dont think it would..... but others think different.

[paranoid airbag]

Kozy said:

stop start rubbish.

Minus 10 points for "asking a question" when you've clearly already made up your mind. If what you want to say is "it's a pointless gimmick" come out and say it the defend your opinion. Or ask a question in a genuinely open-minded way.

Anyways, new battery time if you're having trouble starting?

[Dave Hedgehog]

its worked well for me in london, i have seen improvements of up to 50% increase in mpg, the best car i have used it was a a5 black edition duel clutch, it managed over 30mpg in heavy london traffic, when a 2.0 tdi a5 only got mid 20s

[anonymous-user]

GetCarter said:

I have it in both my cars. There's a button to turn it off.

Same with mine. On short stop-start journeys I just turn it off so that the engine can warm up properly.

[Kozy]

paranoid airbag said:

Minus 10 points for "asking a question" when you've clearly already made up your mind. If what you want to say is "it's a pointless gimmick" come out and say it the defend your opinion. Or ask a question in a genuinely open-minded way.

Except I was asking a question? That question was, 'Is it a pointless gimmick or not?'. Having never owned one, I am not in a position to form an opinion on one, am I?

paranoid airbag said:

Anyways, new battery time if you're having trouble starting?

Tried, still pisses about. It's a dicky solenoid, if it won't start, repetitive flicking of the key at just the right frequency will get it to start. Not bothering me enough to actually get it fixed at the moment but it sure would if it happened at every set of traffic lights!

[TheInsanity1234]

Have the start-stop in my parent's Yeti.

We don't really spend a lot of time stationary as we live in a countryside area, so very few instances of actually stopping, so we don't see much of an difference.

It's rather useful as an anti-stall system, as someone has mentioned above, as my older sister has only just started driving, so she stalls the car every now and then, but just dip the clutch and the engine starts again, no problem.

It'd probably be useful for the sort of driver that buys a little Fiat 500 or Renault Twingo for driving around a city at 17 mph and stopping every 4 minutes for traffic lights, you'd probably get a 50% decrease in fuel consumption as you're not using fuel whilst stopped, but for the motorway commuter, doing 50 miles each way with no stopping for the duration, then I genuinely don't see much of a point to it.

[TheInsanity1234]

garyhun said:

GetCarter said:

I have it in both my cars. There's a button to turn it off.

Same with mine. On short stop-start journeys I just turn it off so that the engine can warm up properly.

This is odd, as I'm sure on SS systems, they won't actually cut the engine out unless it's reached correct operating temperature, amongst various other criteria.