09 Guess Guage

How do you know that you have more than two gallons remaining in the tank? Did you run it out as a test?

Tom

 

It's the bladder and everyone is a little different.

 

From that you can't infer that two gallons remain. It is equally possible that the maximum capacity is reduced by two gallons, in fact more likely because of the bladder.

Tom

 

that's stinky. They could have tried to refine the fuel system some for the 09 models, I am not aware of anyone who enjoys the guess gauge/tank.

I 've gone about 80 miles on a blinking last pip. But that was just a test, I didn't run it dry..but I am sure it was darn close. Better to just fill up on the the second pip instead of taking a gamble.

 

I have an 08' and I'm with you on this one...I drive until I see a flashing pip and everytime I fill up it usually only takes 8 or 9 gallons and that's in summer AND winter, which leads me to believe that there are at least 2 gallons left in the tank. I don't top it off either, I just fill until the pump stops on it's own. I'll never try to test my guess out though...my mechanic told me "don't run it dry, and don't run out of gas in this car, you will be screwed...put gas in it when it tells you to".

 

The bladder has incredible elasticity in the Summer and is seemingly quite stiff in the winter. I have put more than 12 gal in the tank in the summer, however the whole fuel system is incredibly complicated and there are warnings in the archives on overfilling! Be reasonable, fill the car with 2 pips or so knowing that you have plenty of time now to search for your best price. Remember NO fuel guage is very accurate and most are somewhat mis-leading.

 

You don't know that the bladder holds 11 gallons. That is the central flaw in your thinking. The gross capacity of the Prius fuel tank is 11.9 U.S. gallons. The usable capacity is less, due to the bladder and fuel pickup point. How much less varies by vehicle, temperature, and possibly the phase of the moon. The only way to know for sure is to empty the bladder, at which point you are out of fuel. Even if you do this as a test, it doesn't mean that you will know the bladder capacity on the next day, when the temperature and other factors may have changed.

The fundamental point to understand is that you don't know how much fuel your bladder holds. Furthermore, there is no way to know. All you know is that it will run out at some point, and when the fuel gauge gets low, it's time to buy fuel.

Tom

 

I don't know of any changes in that area. The bladder varies from one Prius to another, and there is a calibration procedure that can introduce variation in the gauge, so it's not surprising that this Prius is different than your previous Prius.

Tom

 

I don't know about the motivations of Toyota, but I have been driving my 2007 Prius for a year now and most of the time two pips = 7.5 to 8.0 gals to fill up. I just accept the fact that I need to fill up every 400 miles. After 35K miles I have not seen it work much different than the first days I had it. I will say that I have stretched it to one blinking pip at close to 500 miles and put in more like 9+gallons but I still can't tell you how much was left.

Just count on a 400 mile range, which is better than anything I've owned except the diesel that carries 100 gallons. Filling that one up twice on a Charolotte run equates to about 0.5$/Mile @$4.50/gal) . Compare that to my Prius that equates to about 0.05 $/mile (@$2.50/gal) and suddenly the bladder thing just doesn't bother me .