I can never fill my tank completely?

[yarisitis]

So I was at the gas station with my girlfriend and she was filling up her 2000 Echo. The tank was almost empty and the gas marker was just above the E. So when she finished filling up I noticed that the pump had stopped at 10.x gallons, and I realized that I'm never able to fill up my 2008 Yaris with that much gas.

Every time I fill my tank up, the pump always stops at around 7 to 8.5 gallons. At times I've driven with the last blinking gas bar for 15-20 miles and fill up thinking that my tank is nearly empty, and the pump still stops at around 8.5 gallons. Why is it that I can't seem to pump more gas than that?

I've always wondered how some of you get 400+ miles on a tank of gas and 80+ miles on the first gas bar, and now I'm thinking it's because you guys fill your tanks up almost completely to the 11 gallons. I usually get around 320-340 miles on a tank and am now thinking that I get that little because I'm only filling up with around 7-8 gallons.

What gives?

[CTScott]

The spec on our tank capacity is 11.1 gallons. Topping off so that the filler pipe is almost full lets you put about 12 gallons in.

The fuel gauge is a bit squirly on the Yaris. I've done at lot of work with getting more data from the fuel sender for my YarGauge project to be able to report the number of gallons left and how many miles/km you can drive before pushing. What I've found is that the fuel sender stops registering when you pass about 10.2 gallons on filling and stops registering with about 2.5 gallons left in the tank.

So, I believe that what you are doing is filling very quickly after seeing the flashing single bar. There are actually two modes of flashing - fast as slow. When it starts to slowly flash, the tank has about 4 gallons left and when it starts to flash quickly you've hit the 2.5 gallon mark.

[TLyttle]

I'm working on my third fuel gauge sender, and it's going too, ie, something is wrong when one has 260k and the gauge registers the full 8 bars. Also, I don't fill past the auto shutoff, as discussed here before, and the damage to the carbon capture system. 500k (300 miles) to the tank is fine, why push one's luck?

[CTScott]

I'm working on my third fuel gauge sender, and it's going too, ie, something is wrong when one has 260k and the gauge registers the full 8 bars. Also, I don't fill past the auto shutoff, as discussed here before, and the damage to the carbon capture system. 500k (300 miles) to the tank is fine, why push one's luck?

What's the failure mode of the senders? The only vehicle I have ever had one fail on was a Subaru, and with that one the sender had a dead spot from 3/4 to 1/2, where the gauge would just drop to zero through that range. On that car it happened after I left the car sitting without driving it for about 6 months.

[sickpuppy1]

CT, I know you have alot more experience than I do on these things, but the manual say when it slow flashes you have 1.6 gallons left and fast flash is 1.1 gallon. l routinely will let it go till it slow flashes and fill fairly soon after that. Usually putting in 9+ gallons. Last night was the 1st time I hit the fast flash and it clicked off at 10.4 gallons! That made me nervous,lol ( I ended up with 10.8 gallons just to round up to the next dollar) I always fill slow, like the slowest detent on the handle.

[CTScott]

CT, I know you have alot more experience than I do on these things, but the manual say when it slow flashes you have 1.6 gallons left and fast flash is 1.1 gallon. l routinely will let it go till it slow flashes and fill fairly soon after that. Usually putting in 9+ gallons. Last night was the 1st time I hit the fast flash and it clicked off at 10.4 gallons! That made me nervous,lol ( I ended up with 10.8 gallons just to round up to the next dollar) I always fill slow, like the slowest detent on the handle.

The manual is a bit off from my experiments. I actually completely emptied Crashy's tank (literally bone dry, as I removed it to check out the fuel pump/filler), and filled it up one precisely measured gallon at a time.

Perhaps though, the difference has to do with the point where the sender can no longer pickup fuel, since I did not actually experiment with finding where the engine stalls.

[sickpuppy1]

Well either way, last night was closer than I ever want to get again to running out of gas,LOL My fat a** aint into pushing cars to the gas pump and its an embarrassing phone call for back up,LOL

[eTiMaGo]

my "quickly flashing bar" comes on when I have about a quarter of a tank left... so I know I can do about 50 miles more before I really have to refill. Or, like last month, I might think I have just enough to last me until tomorrow morning, and run out of gas on the way home :laugh:

[advocate]

The mystery that is our fuel gauge...

I don't even bother with the silliness. As soon as it's flashing I fill it up.

[TLyttle]

CTScott, the sender simply hangs up. The first one hung up at 6 bars, the second at 5 bars, this one hangs up at full. Eventually (after burning off a half-tank or so) they drop to a fairly accurate reading, except for the first one: it left me depending on Toyota to come get the car, out of gas, with 6 bars showing. Trip meter is all I use now, the gauge is pointless. I had an old Analog gauge system in an older car that registered when the fuel slopped from one side of the tank to the other near empty...