Problem with Scan Gauge E
 

I finally bite and bought from here. Price were decent.

Well I hook to my 2000 F350 everything is perfect expect MPG average issue.

It work but once you turn off it erased. Is there way to get MPG AVERAGE stay there until you reset when refill tank. Cause it would help me know what mpg it get to 1 tank without restart itself every time you turn on key.

There should be a few different gauges for average mpg. "current" gives you your average since you started driving that trip, "tank" gives you your tank average, "today" gives you the average of all the trips made that day. I'd imagine you're just looking at the current average. This is the "AVG" that shows up on the SG-E's main display. I believe if you hit the menu button, then the lower left button you can get to the other averages.