Follow up to my original question, I still haven't found a satisfactory answer to my first question, but my second question is a bit puzzling. I reset both Trip A and Trip B after filling up and for a couple of days both Trip A+B registered the same mileage. Today, however, I was on my way to work when the Trip A computer reset from the recorded mileage to .8. I didn't touch the reset button,(at least I don't think I did), I'm going to have to monitor the Trip computer a little closer to see if it happens again. The computer is useless if it resets with out manual input.