So a couple of things bugging me. On the new ICE system, no matter what is ticked or not ticked, I cannot reset the mies on Trip A or B without it also resetting the avg fuel reading. Which takes me to point 2 -
That little knob that used to be pressed to reset the miles on the Trip A or B, now when you press it the coolant temp changes to something about High Coolant Temp? What possible use is that?
I’ve had the same issue with the trip meters since I bought my ND3 in 2024. I first reported it here: ND3 Software hoping that a software update might fix it but none of the ones I’ve done have helped. My dealer has also come up with nothing, either saying “that just how it works now” or wanting to replace the dashboard cluster, which I was loathe to do when the car was new. I really should email Mazda UK but never got around to it.
And as far as I remember that push button has always shown high coolant temp, even on the ND1.
The push button turns the Temperature Gauge reading on or off….. might as well leave it on all the time !!!
To reset the milage/average fuel consumption you must select Trip A or Trip B on the display and press and hold “INFO” button on the steering wheel controls. That will then reset either A or B.
In addition in “Settings” you can select “Synchronise Trip A reset to fuel mpg”…. or words to that effect !!!
Except that the “Synchronise Trip A reset to fuel mpg” checkbox makes no difference. It resets both miles and mileage when you hold the Info to reset.
The push button was used to rest trip miles in the ND2. This is a change to what it now does.
The MPG reading has always shown the fuel consumption based on driving style since the trip was last reset, rather than showing overall average fuel consumption of the car. You can enable a setting in the main display screen which shows MPG specifically for the last journey each time you switch off the engine, which I find is much more useful than the overall average anyway.
I haven’t tested myself, but the synchronise checkbox may relate to whether the centre display MPG is also reset or not when the instrument MPG/trip A are reset. From my Mazda Connect manual:
Setting to reset or not reset the linked average fuel efficiency indicated in the instrument cluster and the fuel efficiency history (current) on the centre display when tripmeter (TRIP A) is reset.
In the previous iteration of the ICE, you could reset trip mileage on both Trip A and B without affecting the fuel efficiency history. I know, because on my ND2 I left it for over three years!!! Averaged 50.1 in case anyone cares….
In this version, that fuel efficiency history (the bar graph) resets to zero when holding Info down. It also resets the avg fuel in both Trips A and B. Previously there was (and actualy still is) a separate reset for the history.
The checkbox sync makes no difference.
If I have missed something then please correct me!
I have just checked on mine. With link option unchecked under fuel efficiency monitor, I reset both my trip A and B on the instrument cluster. My average MPG on the instrument cluster has reset, but the average in the fuel efficiency monitor remains as it was. At the end of each journey I see a graph on my centre display showing my average overall MPG as well as the MPG from my last journey.
That’s strange. When I do that mid journey, the historical milegae resets to – and the number that was displayed pops into the most recent slot and pushes the others down one. At the end of the journey, I am pretty sure that it shows the same info you get but the two figures are the journey v when the reset was last hit, not an overall MPG unless I have not reset with the Info button.
I will report back with more once I’ve been out for another drive, to confirm further. I reset the trips using the info button on the steering wheel. My MPG is only 37 as I do quite a few short trips, which still shows on my fuel efficiency monitor. I have a separate option to reset the MPG on the fuel monitor. I agree it’s not very clear lol 
I can confirm the following: with link option unchecked, resetting trip A & B does not reset the MPG on either the instrument cluster or in the fuel efficiency monitor. To reset the MPG count, I need to enter settings in the FEM select reset fuel data (or words to that effect). Once I reset that way, the MPG count resets on the cluster and in the FEM. The previous value on the FEM then moves one slot left on the bar chart and the far right bar (current) is set as 0.
I assume checking the link to A/B box enables the FEM reset when trip is reset. That’s how it works on my 2025 Homura anyway.
Hope that helps 
Well then, I have a fault! Mine is a 2025 Primeline, not sure why that would make a difference though.
From other remarks I have seen, I may not be the only one. I might try and do a short video, post it on here to check I am doing things correctly.
Thanks for your answer. Most helpful.
So today I recorded what happens in mine. the sync box was unticked.
Unfortunately it looks like I can’t upload videos onto here!
In the first video, I reset with a long press on Info. The distance is zeroed, the dashboard MPG (37.0) resets, as does the same 37.0 in the Current position on the bar graph, moving one slot left. The ‘Avg for Current Drive’ figure on the right is unaffected.
A short drive along and I reset it again - same thing. New Current (now 43.0) resets on dash and bar graph, moving one slot left. Because the motor has not been switched off, the ‘Avg for Current Drive’ continues to show a correct amount.
So - on the old ICE, you could reset the trip meter, and the Avg MPG on the bar graph remained unchanged, as mine did for over three years. Meanwhile, you could also reset the MPG on the dash and the bar graph would still be unchanged. It had a separate reset function. On this new ICE, the only thing unaffected by a reset is the ‘Avg for Current Drive’ figure on the right. And that of course DOES reset once the engine is switched off.
What I would have hoped is the right-hand figure on the bar graph remains regardless of resets with the Info button, but that does not seem to be the case. I accept the addition of the ‘Avg for Current Drive’ which wasn’t on the old model.
Is mine the same as yours @MintyRox ?
The “zoomed in” display for coolant temperature is for people who like to take their cars on tracks etc. It is there to allow the driver to see if the coolant temperature is starting to climb before the engine overheats significantly.
The essence of how the FEM graph looks and works on mine is the same as yours, in that the right-most bar on the graph represents the current average MPG since it was last reset. When resetting the MPG data this value moves left one slot and the right bar resets to zero. What differs on mine is that resetting the trip on the instrument cluster does not reset the MPG data on either the dash or the ICE screen - to reset my MPG and zero the current value I need to enter the settings screen in the FEM and select the option there to reset, which zeroes the MPG data on both displays.
I can only surmise that your sync check box is not working as it should, and although you have unticked the option the trip reset is still syncing with the FEM and resetting everything.