Biggest MPG error you've seen on your uncalibrated gauge? (Nissan X-trail SG/UG)

[mechman600]

^^^What he said^^^
And also set the power down mode to "COM" instead of "KEY" or RPM".
This setup works great on the Civic. Combined with the kill switch, it's awesome. I can EOC for miles (vehicle speed keeps reading when you shut off with a kill switch as opposed to the momentary loss with a keyswitch), wait at a light for 5 minutes, and the SG is counting the whole time, not shutting off.

[Vman455]

So, I had something interesting happen with my Scangauge yesterday. I had just pulled onto the freeway at the start of a 500-mile trip, looked down, and noticed that my average for the trip so far was reported at 106mpg! Then I looked at the instant mpg: the Scangauge was reading 9999 under throttle, and continued to do so for several miles, until I pulled the cord and let it reset. Anyone else had this happen?