ford explorer2009 fuel mileage reducing

Hey guys does anyone experience this, My 2009 EB used to have 520KM reading once the fuel tank is full. I have noticed notice that every time I filled up the gas it is keep on reducing the latest is just 471 KM on a full tank fuel. Don't know is there a calibration wrong or something that I need to be done.

I'm still having the same problem I tried changing diffrent brand of gasoline and still the same

To my understanding the computer keeps track of the mpg for the last 1000 miles or so and uses that to predict the mileage you will get from a full tank. Has your fuel mileage been going down due to type of driving or different temps?

That will change depending how you drove in the past few hundred miles or 1000.
My v8, on normal days will show 320 miles with full tank.

After pulling a heavy trailer for a while, it will go down to about 200, and then it will recover back to 300.

If you have been driving mostly in town lately, or the temperatures dropped significantly, or your local gas stations changed the fuel blend from summer to winter, your mpg will suffer.

Thanks folks I'm still observing it but the difference is almost 100KM now compare to when I bought it.. it's used to be 520KM fuel tank capacity now its just over 400.. No changed in driving style and I never used it for towing or hauling purposes.