What actually resets the "Since refuel" MFD?

Is there a switch that is activated when you open the fuel door that causes the reset of the "Since refuel" MFD ? Or, is there a float switch in the tank, or, what ?

I would hope that it's not triggered by opening the fuel door, since that doesn't have to result in any fuel being put it, say for example someone opens it by mistake.

Viz

probably software routine, store fuel level at shutdown, compare at startup.. if changed dramatically = refill.. or mebe it just resets it when level rises more than a trigger point.

I can confirm that simply opening the fuel door does NOT reset the MFD. It must go off of the difference between the shutdown level and startup level.

I have left mine running during fillups and it resets usually before I get out of the station lot or sometimes just after I'm on the road. Or at least that's my recollection. I usually keep my radio display on the screen that shows mpg since refuel.

I generally record the stats for every tank just after I fill (MPG, miles, odo, etc.). It seems to me that the "Since Refuel" screen doesn't change when I start the car after a refuel but it does resets as soon as I move the car.

^ My observations too. Once the computer detects that the miles to empty has gone up from the last stored number, it resets once the car moves. I'm glad there's that delay, just in case I miss something when gathering my stats and entering into fuel log app once I start the car after refuelling but before driving off.

From my experience, once you put the car in gear to drive, that resets it.