Fuel gage

Lots of posts in other threads in this forum. Has alot to do with the tank system which is not a simple metal container. Inside the metal tank is a bladder that expands as gas is introduced and contracts as gas is removed. This is to eliminate most of the gas vapor over the emptying tank and thereby decreasing car emissions when refueling.

Thus a simple bouy system doesn't work to measure remaining gas. The system that Toyota came up with results in a great deal of "reserve" However, it has been observed that it is NOT a good idea to run out of gas in this car. Limping to the gas station on battery alone runs the risk of excessively deep discharging of the Main Battery Bank.

 

Figure this one out:

I filled up earlier last week allowing the pump to click off. The fuel gauge read "full" showing, I believe, 10 bars. I drove the thing about 100 miles before the first bar disappeared (leaving 9 bars lit up). The MFD showed about 54 mpg.

I am now going to record how many miles I get for each bar on the fuel gauge.

 

Finding a rhyme or reason to how the bars decrease on the gauge - prefix, anyway - is like figuring out Hawking's Theory of Everything before he does.

On the up side, with spending between 5 and 10 minutes at the pump, I consistently get 10+ gallons into the tank, and I don't even pay attention to the gauge if I'm below 500 miles (unless, of course, my MPG is below 48 or so, which is rare). My only suggestion is to go as far as comfortable for yourself, and attempt to consistently achieve that.

-m.

 

When I fill the tank completely, I go 150-175 miles before the first square in the gauge goes off. From then on the squares disappear faster, and slow again when I reach two bars.

The othe day I parked on an incline with two bars on the gauge and when I came back six hours later I had one blinking bar! The gauge never returned to two bars and I filled up 30 miles later.

 

When I FILL the tank, I've gone as far as 205 miles before the first bar went out. That was averaging 54-odd MPG on a trip.

The only way to be sure the tank is full is to wait until a small amount of gasoline is visible when you stop and pull the filler out. Too much, and it will leap out at you. I've settled on 25 cents worth of gas as my add-then-check amount when I'm close to being full, but that's getting to be a little more gas each time due to price decreases, so I may have to go to 20 cents soon.

The Wal-Mart gas I got Friday for $1.769 is doing OK, much better than the previous Hess tank. Too bad I didn't wait until Saturday for another penny decrease, but I'll gladly put up with disappointments like that for a return to $1.199 or less sometime down the road...

 

Yes, I've noticed that; I haven't seen a bar that disappeared light up again.

As soon as I get down to one bar, I start looking for a gas station. I've just been letting the pump click off so far. Maybe one day I'll see how much I can cram into the tank after the pump clicks off.

 

You know, I was back in Michigan when the prices went down. Out there, it was down to $1.75, and in Ohio, $1.69. Needless to say, I was quite upset to come home to the same prices as when I left! Right now I still can't find it for less than $2/gal.

-m.

 

Yeah, its seems that gas prices in the DC area are first to spike upwards higher than a most other areas of the country and last to fall when other areas have already dropped their prices. Gasbuddy.com consistently showed the Germantown-Gaithersburg MD area commanding the highest gas prices in Maryland, though they have fallen back .05-.10 cents since their peak prices.

 

[font=Lucida Console:76dd18dfbb]For people in Northern VA, Costco is usually about $0.15 less than local average. Just filled up @ Sterling (VA) Costco for $1.839 Saturday 06/19[/font:76dd18dfbb]

 

Having read this discussion, I experienced this problem yesterday.

I had one level left after 430 miles on my 05 Prius. I stopped by a cheap gas station ($1.89/g) to fill it up and tried to figure out the result of my third tank. To my surprise, it stopped at 5.5 gal. This reminded me of the problem because my MPG for that tank had been about 50. I believed I should be able to keep pumping more, but it stopped almost immediately every time and I gave up at 6 gal after a few tries. Back into my car, I saw one level left to the tank full.

Hence I'm pending the MPG math for these two tanks.

 

I have had the exact same problem as Priusist recently. The tank only took about 6 or 7 gallons, and the gauge never went all the way up when I got back in the car. On the ensuing tank, the computer calculated about 33 mpg, but my calculations were off, because the tank was never really full, according to the guage.

This fuel tank thing has really bothered me. My first tank from the dealership I went 440 miles and was able to put about 8.5 gallons back in after. From that point forward, I have never been able to go more than about 325 miles before I get the low fuel warning!! And when I fill up, it may only put 6, 7 or 8 gallons in, but can be very inconsistent! Does the tightness of pump in the side of the fuel tank hole make pressure build up and stop the pump prematurely?? Every time I try to top off, it doesn't really let me... I remain very frustrated at the fuel tank/guage design.

 

I had a problem only once having fills consistant with the computer MPG until the last couple of times. The last 2 it clicked off about a 1.5 gallons early. So I kept going, 5 drops at a time it seemed. Gentle on the handle (like trying to hold computer selected EV mode ;-) ). I'm wondering if the cold is keeping the bladder from expanding as much as usual. I did pull the nozzle out a few time in case there was air back pressure or something but it didn't seem to help. Never a hint of spit back or a 'near full' sound in the pipe.

 

I've decided to ignore the little squares entirely. We reset our "B" odometer to 0 when we fuel up and refill around 400 miles (640 km). Am not going to be a slave to a computer...... hey, wait ...the whole vehicle is a computer. Sorry Prius Master!

 

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I was doing my fourth tank two days ago and it went back to normal. With the last one level blinking and "add fuel" showing up on the monitor, I was able to pump in about 10 gal after 330 miles for the previous tanl of 6 gal.