fuel gauge/bars

Normal behavior, nothing to fix. Short answer: it's attributable to the flexible fuel bladder.

This is one of the most commonly asked and answered questions on PriusChat. The Search function works very well.

 

Just how does the flashing pip work, that is... what turns it on and why or how is it so unpredictable. Right now I'm hualing around 3-1/2 gals. of gas and wanting to empty my tank, in an attempt to learn more about this situation. (I'm at 65 miles after the last pip began flashing).

I've got the scan guage, but assumed fooling with the fuel & miles remaining would be a crap-shoot.

Any words of wisdom, from the more experienced Prius owners.

 

It's not unpredictable. It works quite well. When you get the flashing pip, you need to get gas right now. The Prius gas gauge does a good job telling you when the tank is getting low. What you don't know is exactly how much fuel is in a full tank. It varies.

Tom

 

It does depend on the baldder. Ive got between 380 and 475 miles when the blinking starts. It takes the same 8 to 9 gallons.
I have found that I get the best milage when i got the Auto climate control off.

 

Did you have a bigger tank fitted? Everyone else says they have a 11.5 gallon tank according to the book.

I see you have already been told about the bladder and how the gauge is very good at telling you when to get fuel, the handbook in your glove box also says, like just about every cars handbook, keep the level of fuel in the tank above 25% full. For this reason I always fill up at 2 bars on the gauge. You can often get more fuel in if you pause after the pump clicks off, wait about 30 seconds then fill again. This lets the air out. Shake the car from side to side can help too. Beware, this may cause harm to the vapour recovery system but it may not.

Fill past first shut-off at your own risk.

 

Not sure why you resurrected this old thread. Book says 11.9 gallons, not 11.5, so 12 is a reasonable value.

 

A reasonable value for what? Gross capacity? In that case yes. Certainly not usable capacity in the North American model.

Tom

 

Neither am I Shawn, it came up in a search of unread posts, baffled. Should we let it die again?

 

Gross capacity, which is what the manual lists and what one would use for other vehicles as well. Yes, it is true that the NA Prius is inordinately handicapped with regard to its useful capacity.

 

To the OP...

Even though you only had one PIP yet I would say you could probably run it to about 500 miles on that tank before the ICE cut out due to lack of fuel (assuming the bladder was behaving at last fillup to a full tank).

Assuming no bladder problems, think of it like this. Your fuel tank is much like an aquarium, imagine taking a typical aquarium and pouring a gallon of water into it. You'll notice it'll fill up what... maybe 1/2" of water across the bottom? Likely hardly enough that the pump can pick any of it up. So, let's say your 11.9 gallon rated capacity tank actually has an effective 10 usable gallons in it (again, asuming a full tank with no bladder problems). So, also assuming your MFD is accurately calculating your fuel mileage and your driving style is consistent throughout that tank, you should be able to multiply your MPG by the 10 gallons and estimate your usable range.
50 MPG = 500 miles range (estimated).

That's what I go by.