Mine sometimes works in even within a couple of minutes of driving, but usually needs a few braking ‘events’ to charge the battery.
The more electrical drain you have running, the less likely iStop is to kick in, and the shorter it will last. Things like rear screen heater, heated seats and AC will affect it. I’ve noticed since installing a dashcam that has affected it too.
More than once, I’ve pulled up at a red light and iStop hasn’t operated, I’ve turned down the temerature control or the heated seats, or turned the blower control away from demist, then it has.
Having the air selector turned to the demist position, which turns the AC on with it, will almost always prevent iStop from kicking in.
Have had similar experience with 2014 Mazda3 Sport Tech 97k miles - likely to be same system on ND. The manual gives a long list of things that stop i-Stop but there may be more. As JJW said, the more electric power you consume, the less is works. We find it starts to kick in after about 10 miles of driving from cold (mainly at 50+ on country roads). Worth visiting the dealer, or specialist, for them to check as it could also be a problem with a control module - we had to replace the rear control module in December and the i-stop has worked better since then! PS - failure of control module stopped all electronics at the rear of the car including central locking, fuel gauge, ABS, TPS (ABS) and boot release! Took £300 of labour and new battery to sort it out. PPS glad my NA and NC are simpler!
Is it fair to regard Istops are expensive pesky unreliable piles of cack?
What is the point of having a pretend lip serving fuel saver that causes expensive issue chasing?
I guess the Green moonhowling lentil munchers think they are ever such a good thing.
If they care so much for planet Earth why drive a petrol only 2 seater!
I think a better question is why not have it? It saves me money and it reduces emissions.
It just works on my 2013 Mazda6 Sport and has done for the five years I’ve owned the car. The only time it hasn’t was during lockdown when the car stood unused for weeks. But a decent run would bring it back to life again.
It’s quite clever the way it works - a common misconception is that it increases wear on the starter motor but it doesn’t use it (unlike some more basic systems on other cars). It restarts the engine through combustion; fuel is directly injected into a cylinder while the engine is stopped and ignited to generate downward piston force.
It helps towards my 6 getting way, way better mileage than my NB - getting on for 50mpg on a run - which I still find miraculous.
In any case, if you don’t like it you can always switch it off.
I think there’s something in that, especially if, like me, you don’t use the car daily, in an urban area, at busy times. It’s there because in the conditions of the statutory test it makes a difference to the measured fuel consumption so I suppose the benefit is paying a bit less RFL, whether it saves fuel or not. I’d guess it would make very little difference to mine. It’s a recreational car and rarely in stop start traffic as that isn’t my idea of fun.
Most of the user feedback I’ve heard about it is people fretting about whether it’s working properly or not.
I’m very happy not to have stop start, lane-keeping, autonomous braking, or adaptive cruise control on my 2017 1.5 which makes it pretty much the perfect ND to have as far as I’m concerned:)
That would be a necessary corollary to the battery manager measuring the current in and out of the battery, yes. If the charger were to be connected directly to the -ve battery post then the battery manager would not register the top up and would assume a previously flat battery still to be flat.
Generally speaking, John, I agree, and it seems to me that we had a better idea in older cars that were provided with ammeters. But it is an observed fact that, when the load on the electrics is low, the output voltage of the alternator, and thus the terminal voltage of the battery depends on the state of charge of the battery. Today I drove about an hour or more through the city after the car had sat for about a week, and the voltage at the cigar lighter socket was 14.4 when I started off. I turned off i-stop and during the course of my trip the voltage went down to 13.8, which tells me that the battery was then charged sufficiently. It will be interesting to see the initial voltage tomorrow, when I have to take the car to have the tyres/wheels changed for the summer. I expect that it will be lower than this morning.
Today when i started the car, the voltage was 14.0, but it soon dropped to 12.4 when I got going, and hovered between 12 and 13 on my outing through the city to the dealer for fitting of the summer wheels. It was very cold (6°) but i-stop was working normally, so I believe that the battery was well charged yesterday, even though the readings were lower than I expected.
There is a setting in the infotainment that tells how much Istop saves.
But it’s not terribly encouraging.
When I checked at around 20k mileage it said I had saved the equivalent of……8 (yes, eight) miles.
It could have been actually 30 or 40 saved were it not for the self cancelling additional kerb weight it had to haul around!
OK I’m being cheeky…
I’ll just go and do dinner…
Interested in the argument that this system is environmentally friendly.
How much petrol is saved given that we are told it is pointless to “coast” because the ECU is not stupid, knows we are coasting and stops sending fuel to the engine?
Are people really saying that a starter motor that is used 100 times more won’t wear out 100 times faster? Carbon footprint of producing 100 times more starter motors anyone?
Is it a swivel-eyed urban myth that you need an advanced, more expensive and, by definition, a more resource hungry battery?
How much car congestion is caused by the delay in starting up at traffic lights? Not so much for the individual but globally. This has a price in carbon emissions and economically. Any resultant gaps in traffic will be filled and by extra acceleration.
I got 45 mpg out of my first car which is now over 60 year old technology. So 50 mpg in 2023 is feeble progress.
As of this morning, I’m on just over 10k and mine is at 86.6 miles. And a good 75% of my 10k has been on the M1 when (usually) I’m not stopping at all.
Obviously I am looking at the wrong screen (i.e. the one with the i-eloop animation). On that screen I see when i-stop is ready or not. But I dont see any indication of how many “miles” or whatever I have saved by using i-stop (e.g. your 86.6 miles). Of course, being in Austria, I have the distance units set to km, which selects the crazy litres/100 km method of expressing fuel consumption, which I understand but hate, so maybe that has something to do with it. Alternatively, the fact that I have only driven 880km since new may be the reason, OR that I have turned off i-stop too much in order to ensure that the car keeps up to charge when driving in the city. I have done little motorway driving, and the car often sits for a week unused. This should change if the bl**dy weather would play ball and we could get a bit of global warming!
Please explain what I am doing wrong in getting the display of i-stop savings, or ask for clarification.
It never ceases to amaze me how many different documents there are on the Internet about Miatas. I cant remember whether I have this one or not. But I have seen the p.219 picture with the bar graph before, though never found it on my actual car display. I have never seen the picture on p.223 at all.
Now know what I am looking for I can send a search party out for it. (I think it must be one of the pages selected at the extreme left hand end of the “home” options.) I am guessing that clicking on option (3) changes the Fuel Economy Screens.
As may be obvious to you by now I am illiterate when it comes to understanding icons!
Hi David, go into the fuel economy monitor, then settings and tick ‘Show screen at ignition off’
It then shows the screen below for a few seconds after you turn the car off.
When I first ticked this I thought it would give a summary of fuel used, distance travelled and MPG for that journey, it doesn’t but it does tell you how much you’ve been stopped and how much of that iStop has been on, as well as the total range boosted by iStop. This is a typical commute for me this morning, stopped about 4 minutes, iStop on for about 3minutes. Out of a 30 minute drive.
