Question about filling up

Your gen2 prius has a metal tank with a plastic bladder, when it get's below 72 degrees the bladder starts to contract, when it sit's at 40ish degrees, (winter for you) it contracts sufficiently to decrease the amount of gas the tank will hold, so, as it's getting above 72 degrees these days, the tank will hold more, the overall mileage per tank will increase.

 

The consensus here is to refill when you see one pip left on the fuel meter. At this point, the measurement is not very accurate, could be 1 gallon, could be 3, who knows... go any further and you're tempting the fates.

If you want to live dangerously, try climbing mountains. Trifling about your fuel gauge is pointless and boring. There are much greater problems one will face in life than having to visit the gas station.

 

About a hundred threads worth on this topic.

Nearly all cars have a significant portion of the fuel tank held as safety margin, beyond the low fuel warning. 100-ish miles (or 2-ish gallons on a Gen3 Prius) is typical, though this varies considerably.

But as previously noted, your Gen2 Prius fuel tank contains a flexible bladder, which is infamous for adding considerable inconsistency and uncertainty compared to the already uncertain fuel level of other cars.

You didn't say how far down the fuel gauge you have gone before refilling. While some Gen2 drivers have repeatedly gone far beyond the Distance To Empty = 0, others have run dry with one or two solid bars remaining, well before any low fuel warning. Driver beware.

 

275 seems a bit low to me...i;m usually at 250 with 5 bars left...but when i fill...i fill slowly and burp it as i go...so it doesnt spill out...once the pump clicks off...i go 1 more gallon+/- and thats where i stop...so with 2-3 bars left i'm approaching 300 miles more-less...most of the time...winter less...summer lots more miles...

 

Thats exactly how our 2005 is behaving in the cold weather. I usually fill it at about 1 pip left which is around 270 miles. I fill it slow and stop when it clicks. Never took more than 7.2 gallons so far, even when I took it down to the flashing pip. Haven't owned the car in warm weather yet, but they say you can put more full in and get better fuel mileage in warm weather.