Fuel Gauge????

[tigerpilot]

Here's the setup. Have about 450 miles on this tank. (Getting 54 MPG on this tank) Down to one pip and have driven about 20 miles on the last pip. No blinking yet. I'm not near my favorite brand of gas so....I stop and add EXACTLY three gallons of 'generic' fuel to the tank. No change whatsoever as far as added pips go. Still the one pip. I'm sure that I'll get the approx. 150 miles additional on the tank but I'm wondering why at least two more pips didn't come on. I'm aware that if you run the tank dry you need to add at least three gallons to get the car started.
What do you folks think is going on?
Thanks

[EZW1]

Do a search on here, but I recall reading from a post that you have to put in a few gallons of gas before the gauge will show a new level. Not sure why this is, but believe it is a fact.

[john_dough]

From what I've read about the fuel bladder and from observations on my own Prius, I believe that the gas gauge itself is not the problem, and is about as accurate as most such gauges found on all cars. It is merely reflecting the unpredictable state of the flexible fuel bladder. This web site is a primary reference in documenting complaints about the fuel bladder and will provide you with much useful info (use search function).

[qbee42]

The amount of fuel added was too low to register. The Prius needs a bit more than three gallons to notice the addition.

Tom