Hi Neilda,
That gives me even more comfort about the warmer running in winter.
My fuel gauge does exactly the same as that and the first owner of the car sent it back to the factory 4 times and it never got sorted. I tend to drive until the warning light comes on as there is still around 2 gallons of fuel left in it.
The most annoying aspect of the car is the factory fitted radio - hopeless!!
T