6 Gallons only 3 bars down on the Gas Gauge??? (How accurate is it)

It's not referred to as the guess guage in these forums for nothing!

:deadhorse:

 

The gauge is not linear. The one thing to rely upon is, when the last pip starts to flash the tank is nearly empty.

 

I have had it take 100 to 160 miles (160 km to 250 km) for the first pip to go away, my advice would be to find a safe mileage (I use 400 miles (650 km) as my safe distance) and get gas as soon as I can after that distance.

Actually, it's more of a guideline than a rule... Dr. Peter Venkman - Ghostbusters

 

AGREED. the "guess-gauge" is NOT linear. i will tell you all this. after about 33.5K miles, my tank (bladder) has stretched out. it used to be only 85-ish miles when the first pip went away. now, i can get 120 before it goes. So it's gotta have stretched out a bit.

How i wish the gauge could be linear. We've done a great job with rocket science......you figure we could get a great working gas gauge. In toyota's defense, my cadillac fuel gauge was NOT linear either.

 

I have never seen a linear gas gauge in all the cars I've owned. It seems that they all show close to a full tank for a while then go down dramatically. As for the Prius. For me it has been accurate to the point that when the last pip is flashing and I get gas, it takes 8.5 gallons till it clicks. I also use the rule of thumb and fill up after 400 miles regardless of what the fuel is reading.

 

Same experience here. On my 2009, it seems that the first pip represents 2.5 to 2.9 gallons, while subsequent pips (and I've never gone below 2 remaining) are somewhere between 0.8 and 1.0 gallons each.

 

Personally, I have found that AFTER the "Low Gas Warning" on my 08 Prii starts beeping*RESET Trip ODO1* that I have between 50-60 Miles... I fill up between 40-50 Miles... Check the Cheapest Gas Prices at GasBuddy.com - Find Low Gas Prices in the USA and Canada...

Of course, I STILL have to visit the Gas station more often than that... Only to clean the bugs off the windshield.

The Steaks

 

Today I got the gauge to the blinking mark, drove until the range was saying around 10km - I filled up and only 36.5L went in.... the max is 45L, so what? it started beeping when in the tank where still 10-2L? what??? not very accurate...

 

Have any of your previous cars been any more accurate?

Mine haven't. But I very strongly suspect that many new Prius owners did not pay any attention to fuel gauge inaccuracy in their previous cars.

 

My previous car was a Polo - I would fuel every time the beep of the tank would light up and I was getting about 0-10km range on the board computer. I fueled consistently in this way about 40L out of 45L in the tank. That is, the range was going to 0km, but the tank always had 5L left (as per VW manual).
I was not expecting the Prius to tell me that I have 0km range and then be able to fuel 36L instead of 40L. But, I think, my Polo running on Diesel, has no vapour recovery system (diesel does not evaporate so easily at all) and the tank was simply a "tank" with no bladder.
But if the "tanking" process is so inaccurate, then there is no way to really determine whether the mileage is accurate over a few tanks. I think one has to average over many full fill-ups to even out the errors (tank with bladder, vapours recuperation, shut-off at the gas nozzle, etc.).
And as a rule of thumb, fill up as soon as it starts blinking - not because you are going to run up dry in 2 km, but simply because maybe you get consistent full fill-ups at the pump. This will take some time, I fuel up typically once a month, if I do only commute and not additional trips (which didn't happen in the last 20 days... ).

 

The 2010 Prius has no bladder, at least in the U.S. market, so that shouldn't be an error source any more. As long as the top of the tank is reasonably consistent, you should be able to determine reasonably accurate fuel mileage for every tank. So far, after more than two dozen 'tankings', I am seeing few discrepancies.

On my previous cars (U.S. market), all but one had 8 to 17 liters of fuel remaining when the gauge needle was solidly at 'E' (Empty). The one exception actually ran dry with the needle above E. Compared against this experience, my new Prius is behaving well within expectations.

 

All of my previous vehicles have been an order of magnitude more accurate. Never had a problem with fuel gauge inaccuracy in any previous car with a working sender. The GII has been an experience in that regard...there are problems with both accuracy and more importantly, a completely unnecessary lack of precision in the digital gauge.

It's not the owners' at fault, it is the bladder and the poor digital gauge design that are responsible for most of the trouble.

 

Pakitt's 2010 has a bladder? So the German models have different fuel tanks than the US models?

 

Repeating: All of my previous vehicles have been an order of magnitude more accurate.

I'm speaking of the GII's. This is the forum for them. And the digital fuel indication in the GII's is a detriment whether or not there is a bladder.

As to 2010's, I don't know if they have fuel gauge issues. From some reports I've seen, they do seem to share some venting issues that plague the GII's, despite the absence of the bladder. This is another "feature" I've never had in any other vehicle.

 

My 2010 also seems to have a "guess gauge." Had me worried as it showed more gas being used than was the case. Temperature affects things to a degree as well; I've gained a pip after 20 miles of driving due I presume to warming. The issues is as descried here - lots of miles to loose the first pip, than rapid loss of subsequent pips.

 

That makes no sense. The fuel is always drawn from the low point in the tank, not the high point so if there is any trash in the tank it will be sucked in whether the tank is full or empty.

Kirk