Distance from last setting assumes that you will have the presence of mind to reset the trip counter at every fill up. And if you have a digital trip counter, you will lose all your trip data if your battery should fail, or be disconnected.
Ah. I figured it was something like that. Have been using aCar for many years. I think I used to use something like that when I would file my fill ups. I would actually do the trip readings. At every fill-up I would reset the trip A and keep Trip B going till I was done. However, like all things that tedious, I eventually got lazy/tired and stopped doing it.
Guess Absolute Reading is the way to go and probably the more accurate route.