I used the 97 Saturn Settings Dcb put up as well, but I don't have the 250mpg indication like you do.
I do think my tank mpg is off just a bit, so I'll have to tweak my VSS/pulse setting, but I'll do that in time.
Other than that, my speed is right, my distance traveled is right so...
I think I'm at about 37-38mpg for my current tank, but my big tank shows 34 mpg for the tank so far...
Tapping in at the PCM/ECU was a little bit of pain wasn't it?