Question? Fuel managment

[El_Guapo]

I just install a Yamaha fuel managment system . I install to my gps. My question is, on the gauge it has MPH on top and MPG on the bottom of the screen . I think the Mpg read from the gps speed and the MPH read from fuel line sensor. When the FUEL BURNED TOTAL end of the day, Is the system base on gps or fuel line sensor?

[Bada Bing]

Both, gps gives you distance/unit time and fuel sensor gives you fuel consumption/unit time dividing one by the other gives MPG

[El_Guapo]

If the engine running without gps turn on, would I still get the total fuel burn?