I think that my gas gauge is off

It would appear as if you did not fill it all the way. I doubt that you averaged 70 mpg on the previous tank.

 

A tech training doc that I found on techinfo.toyota.com says this about Prius fuel capacity:

Fuel capacity may vary, depending upon:
"• Temperature - At low ambient temperatures, the resin material
used for the flexible inner tank may lose some of its ability to
expand during refueling. If the outside temperature is 14
F, the
size of the tank is reduced by approximately 5 liters.
• Fuel Nozzle Fit - The bladder fuel tank uses gas pump pressure to
help inflate the bladder during refueling, so the Prius fuel filler
neck is equipped with a rubber seal to ensure a tight seal between
the pump nozzle and the filler neck. If the gas pump nozzle is
dented, scratched, or gouged the poor fit between the pump nozzle
and the filler neck can reduce fuel tank capacity."

Pretty close to the info that's already here, but I hadn't realized that the bladder relies upon pump pressure to "inflate".

 

<div class='quotetop'>QUOTE(ekpolk @ Aug 13 2006, 06:13 PM) [snapback]302707[/snapback]</div>

Actually, it makes sense, given some of the stories you hear occasionlly. i'm just thinking of the ones that start out "I pumped 12 gallons into my prius this morning" and end with "When i removed the nozle, the car started spitting gas back at me". in those cases, the pump clearly inflated the bladder bigger than it wanted to be, so it contracted, spitting out the gas.


But yes, the OP's problem was almost definately the bladder. Many people have posted cases where the car didn't seem to want to take much gas on a fill up, resulting in either a very short period till their next fill up, or filling up more at another near by gas station.

It's kinda nice to know that toyota recognizes the problem as being that of a ednted gas pump... if only they would tell people!


For the OP: i'd suggest finding a "favorite" gas station near home or work or whatever, and trying to always fill up at the same pump... it increases the accuracy of your fillups/hand calculations of mileage to be consistent. of course, this isn't always possible.

 

One more small point, Mr. Whit: the bladder stretches over time (don't we all!), so in a few months it may be easier to fill it.