So it seems we have 4 trip counters in the car. All very useful.

1. The Trip above the odometer in the instrument cluster.
2. The Total Trip in the PCM
3. The Since Refuel in the PCM
4. The Since whatever in the PCM

Its last one that seems to decide when a drive started. But then a stop of a certain interval doesn't reset it. Has anyone figured out what that interval is? I get a 10 minute gas stop, but it seems even a two hour dinner doesn't reset the "Since" . But somewhere between 2 and 5 hours, the car thinks a new trip is in order. Of course you can reset "Since" as you can 1 and 2. Learning these things on the fly. Cannot find anything in the manual.