[joaoesd]

Today, I filled the gas tank (43,5lt - 11.5 galons). I made more than 200Km – 125 miles – and the gas tank indicator is still in Full. Tomorrow I will see if it doesn’t lower, but does anyone have some idea of what’s happening? This isn’t normal, is it? I’m a little worried…
Thank You!

 

[Astrowoman]

In my '05, and I assume this is common, the gas guage is VERY nonlinear. I usually put over 100 mi on before it drops one pip . I'm at 170something now and I'm still only down one pip. I get down to the last pip around 375-400 miles. So, I'd say it is fairly normal.

 

[evander]

I agree. Recently I drove over 100miles and the gauge hadn't shown a drop in pips. This only seems to occur with highway driving.

 

[Astrowoman]

Just for grins, it dropped another pip on my way home last night, and one on the way in this AM, I'm now at 180-something.

I've been told that in general fuel guages are designed to drop more rapidly as the tank empties -- it's less obvious on a true analog guage than with the pip representation (and I think the Prius one is more nonlinear than most based on my perception). The idea is that if it moves very slowly as you empty, you get lulled into a false sense of security and stop paying attention; a noticeably moving indicator commands more attention.

 

[Brian]

The first bar, depending on fuel in tank, and outside air temp, will remain lit for a very long time. I've seen it go away at 60 miles, and the longest was 140, so don't worry, it will eventually go out. The longer the first bar is lit, the faster the others will go out.

 

[DanMan32]

Typically, I get about 55-60 MPG. I usually put 1 gallon more after first clickoff, sometimes a bit more.

It takes anywhere from 150-210 miles before the first pip goes away.
First half of tank, each pip is about 30 miles, last half about 50-60 miles per pip.

Even my Saturn pegged above full for quite a few miles.

 

[joaoesd]

Thank you all! It has happened as you described!

 

[romad]

In my '05, and I assume this is common, the gas guage is VERY nonlinear. I usually put over 100 mi on before it drops one pip . I'm at 170something now and I'm still only down one pip. I get down to the last pip around 375-400 miles. So, I'd say it is fairly normal.

Actually, all the fuel gauges in cars are non-linear. They are set up to drop very slowly for the first half of the tank, and then to drop faster for the last half. The auto makers do it this way because a linear guage would drop fast all the time and upset the customer.

 

[Astrowoman]

Actually, all the fuel gauges in cars are non-linear. They are set up to drop very slowly for the first half of the tank, and then to drop faster for the last half. The auto makers do it this way because a linear guage would drop fast all the time and upset the customer.

Yes, but I do think either the pip representation emphasizes this or the Prius gauge is more nonlinear than average.

I thought the psychology was more to get you to pay attention to the end of the tank then not scare you at the beginning... is this one of those girl/hag optical illusion things?

 

[DanMan32]

In my '05, and I assume this is common, the gas guage is VERY nonlinear. I usually put over 100 mi on before it drops one pip . I'm at 170something now and I'm still only down one pip. I get down to the last pip around 375-400 miles. So, I'd say it is fairly normal.

Actually, all the fuel gauges in cars are non-linear. They are set up to drop very slowly for the first half of the tank, and then to drop faster for the last half. The auto makers do it this way because a linear guage would drop fast all the time and upset the customer.

So how do you account for the Prius gauge, that does the opposite; fast at first (after the initial pip), then slows down?

 

[romad]

So how do you account for the Prius gauge, that does the opposite; fast at first (after the initial pip), then slows down?

I haven't noticed that on mine. After the last fillup (22 mpg), it hadn't dropped at all after driving 50+ miles. Since it is my wife's car, I'm not in it everyday.

 

[Astrowoman]

I've been watching mine carefully and it actually seems to be a steady, slightly accelerating drop after the first pip. By the time I'm down to the last two I reckon I'm about 2 gallons above the "reserve".

 

[ehurtley]

Non-linear.

For comparison, my '99 Hyundai Accent (average 35mpg, 10 gallons of usable tank capacity,) acts as follows:
100 miles: needle still beyond the 'F'.
150 miles: needle just at the 'low' end of the full pip.
200 miles: needle at about the 3/4 pip.
250 miles: needle at about 1/3.
300 miles: needle just above the 'E' pip.
350 miles: needle just below the 'E' pip, warning light comes on.

So when I'm halfway through the tank, it still says I'm almost full. In my Prius, it's nonlinear for the first 100 miles, (usually only 1 bar gone, or if I'm having a good tank, it might still say full,) then pretty linear for the rest of the tank.

On that note, today I had the first fillup where both MFD and gas pumped agreed that I got over 50 MPG over the course of the tank. (I've had it where one of the two said I exceeded 50, but not both, before.) The MFD dropped to 49.9 within sight of the gas station, so I EV-mode'd it around the adjacent McDonalds to bump it back up to 50.0. Gas pumped matched MFD calculation spot-on. The gas station attendant filled it one-gas-handle-notch short of full speed, and didn't top off (I'm in Oregon where there is no self serve,) so I'm guessing he either owns a Prius, or fills them up a lot.

 

[DanMan32]

..................from last, running total
First pip off: 180 miles, 180 miles
second pip off: 30 miles, 210 miles.
third pip off: 30 miles 240 miles
fourth pip off: 30 miles 270 miles.
5th pip off: 30 miles, 300 miles
6th pip off: 50 mles, 350 miles
7th pip off: 50 miles, 400 miles
8th pip off: 50 miles, 450 miles
9th pip off: 50 miles, 500 miles
Add Fuel warning, 50 miles, 550 miles.
Car dies: Haven't gotten there, but I have driven 50 miles once. 600 miles.

Actually, the actual divisions are a bit different, I am usually over 300 miles at half a tank, and often get to the add fuel warning close to 600 miles.

 

[majordude]

I've had a lot of cars act this way. I suspect it is a trick-of-the-trade so that car owners think that their cars are getting better gas milage they they really do. You know, "I don't know why I need a hybrid, I can go 100 miles at 110 MPH in my Ford Cobra on half a tank of gas!" (but only 50 more miles on the other half).