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Honda Jazz, HR-V & Hybrid Forums => Honda Jazz Mk3 2015 - => Topic started by: Deeps on April 13, 2017, 06:55:42 PM

Title: Idle stop, on or off?
Post by: Deeps on April 13, 2017, 06:55:42 PM
I have been turning my idle stop off for a couple of weeks, it has made no difference to my fuel consumption other than it has improved slightly (warmer weather?). I believe the idle stop is designed to assist Honda with statuary testing results rather than do the owner any good. I now only turn on the idle stop if I am in heavy traffic where the car will be stopped  for more than 2 minutes. This makes normal driving with short stops far more pleasant and is a lot easier on the car.
Title: Re: Idle stop, on or off?
Post by: Paulwhitt20 on April 14, 2017, 10:31:54 AM
I think idle stop works best when used in conjunction with a hybrid engine. Then it can just do its thing. Such a pity that after pioneering the hybrid car and having three hybrid cars in their range, Honda dropped hybrid technology in favour of the 1.6 Diesel engine and diesels are now doomed.
Title: Re: Idle stop, on or off?
Post by: peteo48 on April 14, 2017, 12:24:11 PM
I have been turning my idle stop off for a couple of weeks, it has made no difference to my fuel consumption other than it has improved slightly (warmer weather?). I believe the idle stop is designed to assist Honda with statuary testing results rather than do the owner any good. I now only turn on the idle stop if I am in heavy traffic where the car will be stopped  for more than 2 minutes. This makes normal driving with short stops far more pleasant and is a lot easier on the car.

https://www.youtube.com/watch?v=k159M8QhCIE (https://www.youtube.com/watch?v=k159M8QhCIE)

I just love this guy. He agrees with you.
Title: Re: Idle stop, on or off?
Post by: culzean on April 14, 2017, 01:44:47 PM
stop - start is another example of fuel consumption tests being skewed by test regimes that are favourable to laboratory testing but have very little basis in real life driving. I have been passenger in stop-start cars and I reckon I would be switching it off as well if I was driving.
Title: Re: Idle stop, on or off?
Post by: peteo48 on April 14, 2017, 03:11:50 PM
I do my own manual version of stop start at certain lights where I know what the sequence is and how long I'm going to wait and, of course, I don't idle unnecessarily but these systems detract from driving comfort and pleasure and at a negligible fuel saving.
Title: Re: Idle stop, on or off?
Post by: Downsizer on April 14, 2017, 03:26:12 PM
Gentle brake pedal pressure is often enough to stop the car without stopping the engine for short stops.
Title: Re: Idle stop, on or off?
Post by: mac_no1 on April 16, 2017, 12:03:34 PM
Whatever the arguments are for reducing fuel consumption it is not the only reason for the system to be there, it is there to also reduce emissions and therefore benefits the driver by lowering their tax liability. Stop/Start if used by all those drivers who have it would also benefit the environment. Thousands of cars or even millions worldwide all stopped at lights burning fuel is no good to anyone whether its for a few seconds or fractions of a minute - use stop start and save the environment! I've had a Vauxhall Insignia with Stop/Start and now a Jazz Mk3 with it and it never bothers or causes me any issues at all. Why turn it off!!!
Title: Re: Idle stop, on or off?
Post by: Deeps on April 16, 2017, 01:26:51 PM
If turning off my stop start is not effecting my fuel consumption how can it be effecting the cars emissions? 
Title: Re: Idle stop, on or off?
Post by: peteo48 on April 16, 2017, 02:13:18 PM
If turning off my stop start is not effecting my fuel consumption how can it be effecting the cars emissions?

I think it's the concentration of fumes at pavement level that is the issue here rather than the global total. Idling traffic does kick out a lot of stuff that can be breathed in by pedestrians or even other road users through the ventilation system so it's why people are often recommended to switch to recirculate mode when in heavy traffic.
Title: Re: Idle stop, on or off?
Post by: Downsizer on April 16, 2017, 02:45:28 PM
I think the vehicles accelerating away from the lights emit many times more pollution than those waiting.  However, "every little helps" I suppose.
Title: Re: Idle stop, on or off?
Post by: mac_no1 on April 16, 2017, 02:47:58 PM
If turning off my stop start is not effecting my fuel consumption how can it be effecting the cars emissions?

Your car burns fuel when idling and stop start is disabled therefore it will burn some be it miniscule amount of fuel and contribute to CO2 emissions into the atmosphere. Maybe not harmful if it is just one car but take into account all the millions of cars on the road then it becomes a much bigger issue. And if the manufacturers didn't include stop start on Cars then your road tax would be higher depending on which band of tax your car falls into. Would you rather pay more car tax! Like I said I don't find the Jazz stop start to be any problem at all but each to their own!
Title: Re: Idle stop, on or off?
Post by: Deeps on April 16, 2017, 03:04:55 PM
I have done my bit by switching from diesel to petrol. I also live in a low traffic semi rural area where my car is only occasionally stationary for a few seconds at a time.....when it is in use.  :-)
Title: Re: Idle stop, on or off?
Post by: culzean on April 17, 2017, 01:04:55 PM
I have done my bit by switching from diesel to petrol. I also live in a low traffic semi rural area where my car is only occasionally stationary for a few seconds at a time.....when it is in use.  :-)

Two of my brothers were lifetime diesel fans and they have switched to petrol and were surprised how far petrol engines have advanced and how quiet and nice to drive they are.

Their only worry is putting diesel in instead of petrol.  I would have thought with todays technology a vehicle would have a chip by the filler to match with chip on fuel nozzle to stop people putting wrong fuel in.
Title: Re: Idle stop, on or off?
Post by: Deeps on April 17, 2017, 01:15:19 PM
The diesel pump nozzle is a larger diameter than a petrol one, petrol in a diesel is easy, a diesel nozzle does not fit in most petrol cars. I owned diesels for 30odd years, never a problem, I always cross checked nozzle, pump indication, and price. The jazz is a doddle, the diesel nozzle doesn't fit!
Title: Re: Idle stop, on or off?
Post by: ColinS on April 17, 2017, 01:15:36 PM
Their only worry is putting diesel in instead of petrol.  I would have thought with todays technology a vehicle would have a chip by the filler to match with chip on fuel nozzle to stop people putting wrong fuel in.
The diesel nozzle is generally bigger than the petrol nozzle so shouldn't be an issue that way round.
Title: Re: Idle stop, on or off?
Post by: Jocko on April 17, 2017, 04:19:26 PM
I drive a diesel van, so have to be very careful when filling that up. After 50 years of buying petrol I wonder how long it will be before I make the mistake!
Title: Re: Idle stop, on or off?
Post by: andruec on April 17, 2017, 07:28:18 PM
Idle stop might improve fuel consumption (slightly). It might reduce pavement level pollution (slightly).

But what it does not do (or only very rarely) is interfere with my use of the vehicle. Therefore I allow it to do its thing. If other drivers are struggling to live with it I can only suggest that they learn how to operate their vehicle properly. My engine is always on and ready to go when I need it. It may or may not be running when I don't need it but I don't care either way about that.

Perhaps if those that don't like it can explain what the problem is the rest of us can tell them what they are doing wrong.
Title: Re: Idle stop, on or off?
Post by: ColinB on April 18, 2017, 10:01:16 AM
I have been turning my idle stop off for a couple of weeks,....This makes normal driving with short stops far more pleasant ...
... these systems detract from driving comfort and pleasure ...
... I have been passenger in stop-start cars and I reckon I would be switching it off as well if I was driving.
I don't understand these comments. Could you guys explain why it is somehow "unpleasant" ? The guy in the video talks about it being harsh on restart (in some cars), but mine operates seamlessly without any fuss and is barely noticeable. Certainly it's not annoying enough to make me want to remember to turn the system off every time I start the car. Does yours do something intrusive or uncomfortable ? Although if you have CVTs then I'd encourage you to turn it off so you don't dazzle the driver behind with your brake lights, that's definitely more annoying than whether it may or may not save a minuscule amount of fuel & emissions.
Title: Re: Idle stop, on or off?
Post by: richardfrost on April 18, 2017, 10:18:11 AM
Although if you have CVTs then I'd encourage you to turn it off so you don't dazzle the driver behind with your brake lights

That is nothing to do with Stop/Start and everything to do with Brake Hold. Just pull up the Handbrake button and the brake lights will go off. Brake Hold is like keeping your foot on the foot brake. It is not the Hand Brake. Or is that different on a CVT?
Title: Re: Idle stop, on or off?
Post by: ColinB on April 18, 2017, 03:04:48 PM
Although if you have CVTs then I'd encourage you to turn it off so you don't dazzle the driver behind with your brake lights

That is nothing to do with Stop/Start and everything to do with Brake Hold. Just pull up the Handbrake button and the brake lights will go off. Brake Hold is like keeping your foot on the foot brake. It is not the Hand Brake. Or is that different on a CVT?
I'm not a CVT driver, but my understanding (from comments in other threads on this forum) is that Start-Stop on a CVT (and indeed autos from other manufacturers) is governed by the foot brake. The engine only remains stopped if the driver has his foot on the brake irrespective of whether the handbrake is on or off. Lift off the brake pedal and the engine restarts. So the brake lights stay on if the driver wants the engine to stay stopped, and hence my comment that I'd be happy for CVT drivers to switch the system off. No, I don't understand why it's designed that way either. Happy to be corrected by any CVT driver out there.
PS I don't think the Jazz has "brake hold".
Title: Re: Idle stop, on or off?
Post by: Downsizer on April 18, 2017, 04:30:53 PM
Colin B is correct about CVT.  As soon as you take your foot off the brake, the engine restarts, regardless of the handbrake.  If it wasn't so, there would be no signal to restart I suppose.
Title: Re: Idle stop, on or off?
Post by: richardfrost on April 19, 2017, 08:36:05 AM
Interesting. I drive a manual H-RV and I guess I assumed it was based on the Jazz.
Title: Re: Idle stop, on or off?
Post by: Deeps on April 19, 2017, 09:01:39 AM
Interesting. I drive a manual H-RV and I guess I assumed it was based on the Jazz.

It is, (a Jazz on stilts  :D ) but as yours is a diesel it will have a totally different engine management system.
Title: Re: Idle stop, on or off?
Post by: andruec on April 19, 2017, 03:09:03 PM
Happy to be corrected by any CVT driver out there.
PS I don't think the Jazz has "brake hold".
You're correct about the CVT and Idle Stop issue. It annoyed me at first but so many people do keep the foot brake pressed when stationary (regardless of transmission) these days that I've learnt to accept it. It never really dazzled me so I'm happy to take the view that if you really are being dazzled you should go to an optician :)

What irritates me most about the CVT I/S implementation is that the engine restarts even if you've selected neutral before releasing the brake pedal. The silly thing is that it will restart if you move the selector out of N so in that case there is a perfectly good indication that you want to move.

As for how much fuel it saves the last time I looked on the web most technical sites were saying that as long as the engine is off for at least two seconds it will save something. Estimates vary but in several 'real world' tests I found it seemed to about five to ten percent for urban driving. That equates to reducing the price of a litre of petrol by 5p or more and I bet most of us would consider that worthwhile :)

However you're wrong about 'brake hold'. My EX has it.

Edit: Re, idle fuel consumption https://energy.gov/eere/vehicles/fact-861-february-23-2015-idle-fuel-consumption-selected-gasoline-and-diesel-vehicles

For a 2 litre petrol engine it's claiming .16 gallons an hour or .6 litres an hour. So that's just over 1p a minute. So very approximately I/S could be saving me 2 a year. Hardly worth worrying about. But if we multiply that by the couple of hundred thousand vehicles on the road that have this feature (assuming most leave it on) and the fuel savings become more significant.
Title: Re: Idle stop, on or off?
Post by: peteo48 on April 19, 2017, 04:31:49 PM
I have been turning my idle stop off for a couple of weeks,....This makes normal driving with short stops far more pleasant ...
... these systems detract from driving comfort and pleasure ...
... I have been passenger in stop-start cars and I reckon I would be switching it off as well if I was driving.
I don't understand these comments. Could you guys explain why it is somehow "unpleasant" ? The guy in the video talks about it being harsh on restart (in some cars), but mine operates seamlessly without any fuss and is barely noticeable. Certainly it's not annoying enough to make me want to remember to turn the system off every time I start the car. Does yours do something intrusive or uncomfortable ? Although if you have CVTs then I'd encourage you to turn it off so you don't dazzle the driver behind with your brake lights, that's definitely more annoying than whether it may or may not save a minuscule amount of fuel & emissions.

I'll come clean here. I have no experience of the Honda Stop Start but my daughter's Qashqai has it and it seems a bit clunky. It's on a manual though.
Title: Re: Idle stop, on or off?
Post by: andruec on April 19, 2017, 04:58:21 PM
The Jazz (at least mine) there is just a slight tremble when it starts back up.

The only real issue I have - and I blame myself - is if I misjudge the traffic at a roundabout and come to a halt unnecessarily. If I realise my mistake I might end up pressing the accelerator at the same time as the engine is shutting off. Obviously there's an annoying delay in that situation. It doesn't happen very often though and I blame myself for misjudging the traffic flow.

But in normal use the engine restarts about as fast as I can move my foot from brake to accelerator so it doesn't cause a problem.
Title: Re: Idle stop, on or off?
Post by: Deeps on April 19, 2017, 09:11:14 PM
You don't realise how intrusive the engine restart is until you turn off the idle stop system. Unless you have no mechanical sympathy and are totally insensitive.  :-)
Title: Re: Idle stop, on or off?
Post by: ColinB on April 19, 2017, 11:54:28 PM
However you're wrong about 'brake hold'. My EX has it.

Really ? Could you describe how you use it please ? Are you perhaps confusing Brake Hold (as described here http://www.jthughes.co.uk/How-To/View/Honda/HR-V/How-to-use-the-Honda-HR-V-brake-hold-option/02279019-149f-47ba-b05b-e589bb30b9ee (http://www.jthughes.co.uk/How-To/View/Honda/HR-V/How-to-use-the-Honda-HR-V-brake-hold-option/02279019-149f-47ba-b05b-e589bb30b9ee)) with Hill Start Assist ? I don't see BH listed as a feature on any Jazz spec, but HSA is.
Title: Re: Idle stop, on or off?
Post by: Kenneve on April 20, 2017, 10:27:16 AM
My stop/start system is always On, but rarely operates because in normal stops, the brake pedal is not pressed hard enough to trigger the function. On the odd occasion when it does trigger, it restarts the instant I take my foot off the brake, as I would expect.
Title: Re: Idle stop, on or off?
Post by: andruec on April 20, 2017, 01:39:04 PM
However you're wrong about 'brake hold'. My EX has it.

Really ? Could you describe how you use it please ? Are you perhaps confusing Brake Hold (as described here [url]http://www.jthughes.co.uk/How-To/View/Honda/HR-V/How-to-use-the-Honda-HR-V-brake-hold-option/02279019-149f-47ba-b05b-e589bb30b9ee[/url] ([url]http://www.jthughes.co.uk/How-To/View/Honda/HR-V/How-to-use-the-Honda-HR-V-brake-hold-option/02279019-149f-47ba-b05b-e589bb30b9ee[/url])) with Hill Start Assist ? I don't see BH listed as a feature on any Jazz spec, but HSA is.
Ah, yes. Sorry.
Title: Re: Idle stop, on or off?
Post by: Downsizer on April 20, 2017, 04:23:51 PM
Really ? Could you describe how you use it please ? Are you perhaps confusing Brake Hold (as described here [url]http://www.jthughes.co.uk/How-To/View/Honda/HR-V/How-to-use-the-Honda-HR-V-brake-hold-option/02279019-149f-47ba-b05b-e589bb30b9ee[/url] ([url]http://www.jthughes.co.uk/How-To/View/Honda/HR-V/How-to-use-the-Honda-HR-V-brake-hold-option/02279019-149f-47ba-b05b-e589bb30b9ee[/url])) with Hill Start Assist ? I don't see BH listed as a feature on any Jazz spec, but HSA is.

I hadn't heard of the Brake Hold feature before.  It sounds rather useful, and I would welcome it on the Jazz.  It seems to operate in conjunction with the electronically operated handbrake.
Title: Re: Idle stop, on or off?
Post by: ColinB on April 20, 2017, 05:43:35 PM
However you're wrong about 'brake hold'. My EX has it.

Really ? Could you describe how you use it please ? Are you perhaps confusing Brake Hold (as described here [url]http://www.jthughes.co.uk/How-To/View/Honda/HR-V/How-to-use-the-Honda-HR-V-brake-hold-option/02279019-149f-47ba-b05b-e589bb30b9ee[/url] ([url]http://www.jthughes.co.uk/How-To/View/Honda/HR-V/How-to-use-the-Honda-HR-V-brake-hold-option/02279019-149f-47ba-b05b-e589bb30b9ee[/url])) with Hill Start Assist ? I don't see BH listed as a feature on any Jazz spec, but HSA is.
Ah, yes. Sorry.

It's very tempting to suggest that if you are having trouble seeing the dashboard buttons and indicators ...
... you should go to an optician :)

But I wouldn't go quite that far. :D :D :D
Title: Re: Idle stop, on or off?
Post by: John Ratsey on April 20, 2017, 10:17:27 PM
I like the principle of the idle stop although I was spoiled because I first encountered it on the Jazz hybrid which has a very smooth restart due to the electric motor. However, the idle stop on the Mk 3 Jazz (or my current HR-V) is no problem provided one remembers a couple of points (i) anticipate the need to move by about a second by reducing the brake pedal pressure (which restarts the engine on the CVT vehicles) and (ii) light brake pedal pressure will stop the car but not the engine which is appropriate for roundabout queues whereas the idle stop is appropriate for traffic light queues. But I much prefer driving in conditions where the traffic keeps moving and the idle stop isn't needed ;D
Title: Re: Idle stop, on or off?
Post by: andruec on April 21, 2017, 08:56:59 AM
But I much prefer driving in conditions where the traffic keeps moving and the idle stop isn't needed ;D
Yeah. I've become quite adept at controlling it at roundabouts. Banbury rush hour varies quite a lot and it takes experience to work out if a queue is slow moving or 'stuck'. Sometimes a long queue for a roundabout is slow moving. Sometimes a short queue is stuck.

The trick on this stretch (https://www.google.co.uk/maps/@52.0722122,-1.3208304,3a,75y,62.03h,90.7t/data=!3m6!1e1!3m4!1sBArFp8iLlrBoWZdV27wfVw!2e0!7i13312!8i6656?hl=en) is to look out for pedestrians hovering around the traffic lights. The naughty monkeys sometimes press the button. How jolly inconsiderate of them :D

I like to let I/S do it's thing but I have to be sure that it will be off for at least 2 seconds to avoid wasting fuel. Still - it all adds to the fun of driving in my view :)