leaving engine idling..? (1 Viewer)

kevenh

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Hi.
I gain on not having to pay out on Starter ring repairs. Being an Old Fart,and only having it on the car over here that rarely gets used... Over the years, on all the vehicles i have driven,the engine kept running until the key was switched off ,so there am i sitting in the car at traffic lights/zebra X's/junctions etc and realise the engine is off. This is where my..Lightning speed reactions come into play.. :xrofl: Clutch ,Key or Key Clutch... 1.I then get a scrunching noise to say the starter motor is fighting the flywheel. 2. I blaspheme,the people who built my/our Dacia Logan MCV in Romania hear this and fall about laughing. 3. OVERIDE it...Sorted. So,its an Age thing,coupled with not reading the owners manual,and having to get the S.I.L. to. A. Find it and B. read it and get it sorted. He has just "Re set " the TPMS. i DID find the Manual................ But its all in....... Portuguese.......DOH !!!:xeek:
Tea Bag
The starter motor in a stop/start based system is redesigned for the new requirement to being used once per journey to several times.
I like to get away from the lights, etc. pdq & it was rare for the car to be at odds with what I needed.
And there are words at this link stop-start-long-term-impact-your-car to suggest the engineers have thought of those situations where I want to go but he car is stopping :eek: :)
 

kevenh

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fwiw I was going to say it's often not a starter motor getting the motor going again but that was a per manufacturer thing so good job I held back :)
My start/stop car was a Mazda 3 ~2015 model with i-eloop :eek: - seemed to have a very low load on the restart of a warm engine after a traffic light engine stop. Mazda
 
May 7, 2016
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The whole point was to reduce emissions in European Emission tests for Vehicle Excise Licence,,Big con,,,doesn't work in the real world.BUSBY.
Who days it doesn't work? The new testing regime using “real world” testing will soon show if it is a con.

On our Audi the engine will restart if you ease the brake pressure a little, without releasing the brakes. I do this when the lights go to amber/red and can still be the first away when they go green, if I want to. I didn’t much like the feature at first but soon found it works fine if you know how to use it properly.

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Northernraider

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Who days it doesn't work? The new testing regime using “real world” testing will soon show if it is a con.

On our Audi the engine will restart if you ease the brake pressure a little, without releasing the brakes. I do this when the lights go to amber/red and can still be the first away when they go green, if I want to. I didn’t much like the feature at first but soon found it works fine if you know how to use it properly.
Regardless off how it activates it's still the starter motor that starts the engine and theres more fuel pumped in on start up than any other time.
 

kevenh

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Maybe a car with a carburettor would use more fuel than saved if it's being turned off and then restarted
but a modern car equipped with stop start will also have fuel injection and additionally, the engine will be up to temperature and not need the same energy as when cold.

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pappajohn

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Never heard that before, the whole point is to reduce fuel consumption and pollution.
There's ALWAYS a price to pay.
Starting an engine uses more fuel than leaving it idling for a short period (traffic lights etc)
Electric vehicles have no emissions...... But the 'manufacture of batteries' emissions outweigh the saving by not using fossil fuel.
That's never in the advertising.
 
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May 7, 2016
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Yep which is why it's always been a stupid idea. The engine uses more fuel on startup than any other time.
I don’t see why that should apply to a warmed up common rail injection engine.

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Northernraider

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I don’t see why that should apply to a warmed up common rail injection engine.
Whether you see it or not is irrelevant I'm afraid. Ask any vehicle tech out there they will tell you the same. Its how the ECU manages the system.
Idling for a few minutes uses less fuel than switching off and then restarting.

Very few cars with carbs these days.

And as the vw scandal proved dont rely on manufacturers etc being straight about emissions etc.
 

Northernraider

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Maybe a car with a carburettor would use more fuel than saved if it's being turned off and then restarted
but a modern car equipped with stop start will also have fuel injection and additionally, the engine will be up to temperature and not need the same energy as when cold.
Not many cars with carbs nowadays

But they ALL use more fuel starting and stopping.
 
May 7, 2016
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Whether you see it or not is irrelevant I'm afraid. Ask any vehicle tech out there they will tell you the same. Its how the ECU manages the system.
Idling for a few minutes uses less fuel than switching off and then restarting.

Very few cars with carbs these days.

And as the vw scandal proved dont rely on manufacturers etc being straight about emissions etc.
As someone who uses a stop start feature it is not irrelevant to me.

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Aug 6, 2013
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Stop/start was never about fuel economy - it's about the zero emissions of a stopped engine. Having said that I would not take the word of a "vehicle technician" about anything. I have never met a recently trained one who fully understands how an ICE works never mind the relationship between fuelling, timing, and starting, whatever fuel the engine burns. There are no carburettors in use on road vehicles - there haven't been any for at least 20 years. None of the present crop of mechanics are trained on, or understand how a carb worked. I'm not convinced that restarting a hot engine requires additional fuel and can't for the life of me think why it would (easing a hot start, if easing is needed, can be achieved by advancing the ignition) but either way it's irrelevant - if more fuel is used it's in putting back what's taken out of the battery. As an aside a smooth restart was achieved on my last Smart car by motoring the alternator - no dedicated starter motor was installed. I don't like permanent auto stop/start - mine is turned off mainly because of the delay when accelerating into a moving gap from a junction on a hill. Something I do at least twice every time I leave my house. At other times I find I can make my own decision about whether it should be engaged or not so I do use it.
 

Northernraider

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As someone who uses a stop start feature it is not irrelevant to me.
The point was you said " I DONT SEE WHY that should apply to a warmed up common rail diesel engine"

I said , whether you see it or not it most definitely does apply to a warmed up common rail diesel engine .

It applies to all engines if they use fuel ?‍♂️
 
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I have stop/start on my car and I leave it permanently on. It doesn't cut in until the engine is warm and takes into account battery state of charge and whether aircon heated demist etc is on. It doesn't cause any delay at lights/level crossings as restarts as soon as the clutch is depressed, obviously I don't leave it in gear, riding the clutch if stationary as some do, as I have had some idiot run up the back of me when his foot slipped, but if I did it just doesn't stop. It does save fuel as is visible directly from the fuel consumption readout. We have a notorious level crossing here which is closed 35 minutes in each hour during the day, so continuing to run the engine is just unnecessary pollution.

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May 7, 2016
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The point was you said " I DONT SEE WHY that should apply to a warmed up common rail diesel engine"

I said , whether you see it or not it most definitely does apply to a warmed up common rail diesel engine .

It applies to all engines if they use fuel ?‍♂️
That is your opinion, I am more persuaded by other arguments.
 
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I appreciate you response, but I'm only asking if it would damage their engines ,,I myself use sites when my leisure battery is running low....
Simple answer... NO.

but if you keep doing it from cold and do not run the engine at normal operating conditions (drive it) in between the idling then you will have a few long term issues start to creep in..
DPF will be unable to regenerate on its own and will require removal and cleaning
Wear on the engine increased due to poor lubrication and an increase in water vapour getting mixed in with the oil which will lead to sludge.
 
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klaatu

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I thought I had read a report by the SAE some time ago which found that stop/start reduced fuel consumption in heavy traffic by around 10%, but I may have made that up :giggle:
 
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Maybe a car with a carburettor would use more fuel than saved if it's being turned off and then restarted
but a modern car equipped with stop start will also have fuel injection and additionally, the engine will be up to temperature and not need the same energy as when cold.
But the engine has to burn extra fuel to top up the battery after each new start.

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kevenh

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But the engine has to burn extra fuel to top up the battery after each new start.
You're generalising. Lots of car models use energy recovery for the start/stop cct ;)

Edit: lots of the objections to Start/Stop have been thought of in the design stage.
 
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You're generalising. Lots of car models use energy recovery for the start/stop cct ;)

Edit: lots of the objections to Start/Stop have been thought of in the design stage.
They still have to burn extra fuel to top up the battery after each new start.

You can't argue with facts.
 
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Is it common rail pumps that allow you to use vegetable oil?

Is a 2007 Peugeot Boxer common rail.
Years ago I used to use vegetable oil in my Zafira I sold it to a friend between us we clocked up 240,000 miles with nothing but oil and filter changes. He sold it to his garage mechanic still going as far as I know.

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Aug 5, 2018
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Is it common rail pumps that allow you to use vegetable oil?

Is a 2007 Peugeot Boxer common rail.
Years ago I used to use vegetable oil in my Zafira I sold it to a friend between us we clocked up 240,000 miles with nothing but oil and filter changes. He sold it to his garage mechanic still going as far as I know.
Most things started going common rail from 2001 onwards and no, veg oil is better left for PD engines. i.e older vehicles.
 
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What has stop start technology got to do with leaving the vehicle running on a campsite to charge your battery ??????
What a strange thread direction.
Oh and the alternator will be charging the battery whether the start stop function depleted it slightly or not, so saying it'll use more fuel is a moot point...
 

TerryL

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Standing back a little and trying to analyse the opinions:-

Idling a modern diesel engine doesn't do it a lot of good unless it is fully warmed up to start with but even then it wasn't designed to do that. Earlier diesels, especially the big old truck engines, but also the big generators, don't have the same problems so should be okay.

As for start/stop, you have to look at the wider benefits but it seems to come down to personal preferences as opinion seems to be equally divided.

But then again I could be talking a load of rubbish! :xeek:

Merry Christmas everybody!

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May 7, 2017
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Engines,/ Stationary Engines that run for hours and at standstill are designed to do that ,normal car, van, trucks dare not designed to do that.
 

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