Since the gauges have been working miraculously for the past 500 or so miles, I measured the mpg.
My rough calculations were in fact correct.
But now I have gas to flee in one, and escape in the other provided the driveway gets tree’d.
Also, if any Oppomeet at the Dragon attendees read this, so far it is still 100% on. If you choose to cancel, Fontana has been fully cooperative, and will refund you fully due to the weather. So far this weekend looks clear.