Fuel Gauge Reading Full After 250 Miles

Your car is probably OK. My guess is that once you have driven 300 miles you will start to see the fuel gauge bars drop down.

If you overfill the tank to the extent that gasoline is spilling out, you have probably added 2 - 3 gallons more compared to normal if your normal practice is to stop refueling shortly after the pump first clicks off.

If damage had been caused to the evaporative emissions system then you would see the check engine light come on.

 

Keep driving. It will go down eventually.

 

Could this be why the locking fill levers have been removed form the pumps here?
Sitting in, or even getting into and out of the car while filling is very dangerous due to static electricity. Make sure you touch the body of the car and of the pump before you touch the hose, petrol burns are very nasty.

 

You can stay outside with the filler. In most locations it is required by law, in all others it is required only by common sense. The Prius has a tiny tank; it only takes seconds to fill it. How hard can that be?

Tom

 

I'm not aware that there have ever been locking fill levers in the UK. Hold trigger to pump.

 

Oh, god forbid, that would be a hardship for us poor Americans.

Tom

 

On country pumps the locks have been left in place but in metro Adelaide all locks have been removed because city people are stupid and might sit in their car listening to music while petrol spills all over the ground. Country people are far smarter.

 

With the way the tank is set up after the overfill there was probably a liquid seal at 1, 2, 3 or more places in the various vent/vapor balance lines. My guess is that there is still a seal in the gas gauge vapor balance line. As the tank level becomes lower the DP on the seal will rise and eventually break the seal. If this occurs I would expect the tank level to move many pips in a short period of time. Of course, with the digital gauge programming, the Prius might not display the actual change like an analog would (similar to the problems people experience when adding only a few gallons to the tank, but in the other direction.)

The only time I've overfilled was in a vehicle 8-10 years ago. While I normally stayed at the pump, this time the station was low on gas and the pump rate was excruciatingly slow. After 5 minutes elapsed and less than half a fill I started doing some paperwork in the car and periodically checking the progress. The pump rate was so slow that the nozzle did not shut off and I found the pump slowly dumping fuel onto the ground. Wasn't much of a puddle, but I learned something useful about the nozzles.

The irony is that the condition that is most likely to result in the driver leaving the pump unattended is a really slow fill, and that is the very condition most likely to result in the pump shut off not operating.

 

I have overfilled cars on several occasions, even though I was holding the filler nozzle. A few times I have had gas spill out the filler. My old Ford Aerostar van was bad about this, but I believe the problem was mostly related to the gas station. The problem went away when the station changed the pumps.

I like to have some idea of how much gas the fill is going to take, so I can slow down near the end. The Prius can be tricky about this since the bladder introduces uncertainty. Even so, I usually know within a half gallon how much my Prius will take. Anecdotal evidence suggests that some Prius are more uncertain than others, but mine is fairly predictable. If the fill goes over the amount I expect, I go on red alert and proceed with caution. It can be a nuisance, but it's better than barfing gas onto your shoes.

Tom