I noticed my Trip B was recently reset. I do not remember doing it. The timing of the reset seems to coincide with 10K.
I believe it has to do with a limit on the number of digits on the display for miles. And I believe the MPG calculation does not reset.
It seems that way. The MPG reading seems to have stayed. My last 600 miles gotta have lower MPG than the grand average of the last 10,600.
My experience is the same--the MPG does not start again at zero when the trip odometer passes 10K and goes to 0.