I Need Help With My ScanGauge 2 Cutoff Setting
 

The default setting is 24 and they recommend leaving it there unless you know better, but also say that it usually works best when it is 4 above the throttle position when the car is off. My Mustang says 16 TPS before I start the engine, so I tried 20 first and I've danced it around and nothing seems to work correctly. Any time I go into stealth mode, ScanGauge says I'm burning .19 gallons per hour. That's the lowest it ever goes to. Doesn't someone know where my setting needs to be?

I can't think of anyone here running a ScanGauge in a Mustang. Have you talked to the company?

Consider that fuel cutoff not registering properly will probably have a very small effect on trip/tank mpg. When I talked to the designer about it, he figured non-registering fuel cutoff would work out to an error of around 0.1%.