Fuel gauge shows I need to get fuel but range shows 90 miles left

[creedz]

I have a 2004 Yaris and the fuel gauge is blinkering which means I need fuel but the range shows about 90 miles left. Also when I turned my car off, and came back to it an hour later my fuel gauge went back up to 2 bars which I think is around 70 miles of fuel but in the middle of driving it went back to blinkering again (there's been other times where my fuel gauge randomly went back up again but it never came back down this quick). This has never happened before so I was just wondering if my range is wrong or the fuel gauge is wrong? 

[Thoric]

My 2011 Yaris 1.0 has the same behaviour - I always assumed it was by design to stop you getting into fuel troubles. When the 8 bars of the fuel gauge reach the last bar it starts flashing. Each bar is one eighth of the tank and I get about 440 miles per full tank, so that last bar should be about 55 miles worth of fuel. It's not incorrect really, but annoying, so I tend to leave the "miles left" number on the display all the time and ignore the fuel gauge completely.

As a comparison I just drove a business car Golf diesel. It flashed up a low fuel warning when there were exactly 70 miles left in the tank. It was also precisely at one eighth of a tank remaining, the same as the Yaris in terms of the fraction of fuel left. So perhaps it's normal behaviour.