How to obtain MPG value with Bluetooth elm327 scan tool?

How to project this function and improve its accuracy when  with elm327 Bluetooth scan tool.

1) Download Torque app on your Android phone or tablet and install it.
2) Open the app and come to the main function menu
3) Select “Setting”
4) Check “Faster Communication”
5) Check “Enhanced MPG Calculation” and this will slow down other sensors
6) Then check “Use Vehicle Fuel Level Sensor”.  It is very important, because the fuel used calculation is not accurate within Torque app.
7)  Exit the “Settings” and enter “Vehicle Profile”.
8) Find out “MPG Trim” and enter the trim value, like 1.27


You can find a good trim value by running the average MPG for an entire tank for both Torque and the car’s display. It’s consistently reporting some mpg better than getting at the pump. The formula is useful in this case.

1/(Car’s MPG) = X/(Torques MPG)
X = (Torques MPG)/(Car’s MPG) = Trim factor

Use your actual calculated MPG for (Car’s MPG), not the MFD numbers, or you’ll just be matching the optimistic numbers it gives. The more tanks and more times you run that equation the closer you can get. You can get kind of close but doing it for a trip but I find the idle time setting up torque and other factors make it less accurate.

There is also a setting called “OBD Speed Multiplier” that adjusts for non standard sized tires, if that applies to you.

You can not expect this $10 or so elm327 device to do much more than you want. After all, it beats the price.