CX-5 gas tank issue

[WiscoMan23]

I have a 2016 CX-5 that usually takes about 13 gallons when near empty. Yesterday, when the miles-remaining said '40 miles' I filled it up and it only took about 10 gallons. My dashboard gauge said it was full, but the range miles read 320 - when usually it will be about 395 when filled. Very strange.
Today I'm driving it and the gauge says it's full but mileage has gone done quite a bit since yesterday.
Any feedback appreciated.

Thanks.

 

[Mazdiod2]

The range computer changes its estimate of remaining miles according to recent driving habits and mpg. I've noticed that at times the estimated range has gone up, because I went from urban driving to cruising on the highway driving with better mpgs, causing the computer to re-estimate the range.

I think the actual capacity of the tank is more like 15 (US) gallons, so I don't know why your tank only took 10 gallons. Gas gauges don't seem to be very accurate to me.

 

[N7turbo]

10 gallons makes sense with 40-50 miles remaining. At 25 mpg it would be around 12 gallons at empty, which is ballpark accurate. Usually my fill-ups would net me 12.5 gallons near empty.