Can't answer your fuel saving question; I don't take much notice; sorry.mum@mazda wrote: ↑Thu Jan 30, 2020 11:46 am It isn't that I don't want to use it, I would be glad if it worked at every junction or set of lights. I am frustrated when it refuses to work. It has been back to the dealer several times, and had a new battery fitted under warranty. I have done 30000 miles in 4 years, so it is not "garage jewelry". It just doesn't work for me.
I would be curious to see what you guys are getting with regards to saved fuel/milage on systems that do appear to function correctly. Anybody fancy posting their data just for info?
But on the i_stop not working front. The battery needs to be well charged. Mine stopped working a couple of weeks ago. My car is Aug 2015 with the original battery. I put it on charge for a few hours and i_stop is now pretty flawless. However, if my journeys are short with many restarts, the battery will need a longer journey to build to a level where i-Stop will work again.
If I were designing the system I would set the i-Stop minimum battery voltage quite high to protect the battery; so I imagine this is what Mazda have done. In an emergency you would need your battery to work and not find it depleted by i-Stop.
If your car isn't behaving with i-Stop I would ask your dealer to check the battery voltage sensor for i-Stop. And also ensure the battery is charging from the alternator correctly. I'm not a mechanic, but if you've had new batteries there must be some other cause.
Looking at your handle I assume female. If so, you may well also have run foul of some garage dickhead who has upset a few settings to get you to spend money. They don't seem to do it to blokes. But in my experience it happens; they loosen earth connections and twiddle voltage regulators (nowadays not possible) so bulbs flicker and blow quickly.