Scan gauge

Who uses your scan gauge for MPG. Mine is all over the map, sometimes it shows 18 mpg, some times it shows 35. What's the trick to get a accurate reading.

 

Make sure you have the settings correct for your vehicle, engine liter size, gas tank size. It usually only takes one or two tanks to get it very accurate. I get within a 0.1 MPG and 0.1 gallons accuracy per tank. Just got back from 2600 mile summer vacation and used the miles-to-empty with confidence.

 

MPG is what you are currently pushing. AVG is the one that shows your average on the particular trip. It starts from 0 every time and does not retain previous values. Trips section will show you AVG per tank