Strange Happenings with my Gas gauge

Happens to me after almost each fill up. Glad to see I'm not alone. I have about 120 miles round trip each day commute. I'll fill up, hit the highway (60-65mph) and after anywhere from 350-50 miles it will drop by 1 bar. I get off the thruway on to a side road and it's magically back up to full.

Head home again, it goes down two bars, then once again when I am off the thruway, it goes back up to full.

It will then drop "normally" after that, rather rapidly by three bars and then it seems to drop one at a time. There have been occasions where it jumps up and down when I am below 1/2 tank.

Kind of makes me wonder how much to trust the "X number of mile before you need to fill up" reading on the Trip selector.

 

Though i did not notice this on my new 2010 Prius, I did notice this on my Camry. I think it has something to do with the sensor as gas inside the fuel tank shifts around when the road is not even.

 

Next time you are going to use a tank of gas at about the same rate of consumption for the whole tank, check the number of miles remaining several times as you drive and add it to your odometer reading to see where it is saying you will be at 0 miles. If that number doesn't change much, then you miles to 0 are pretty good.

Be aware that as your driving changes and the rate at which you are using gas changes, the estimate to empty will change over a period of time.

My experience wit that feature on other cars has been good.