Overfill - What did I do?

[daronspicher]

This was my 4th fillup, so I had expected behavior.

Insert the nozzle, start it filling on the lowest notch, expecting between 8 and 9 gallons it will shut off.

at 8.711 gallons, it clicked off. I was down to 2 bars showing on the guage before filling, so this is exactly what I expected.

To be fair to my fillup, I will give it another little splash or two, so I grab the handle and it clicks off right away. No (or little) gas into the tank. Repeat, same deal. So, from my other 3 fillups, we are on level ground to this point.

Here's where it goes wrong.... or different.

I pulled the nozzle out about 1.5 inches, it's still inside the little hole way in there, but now, I squeeze in over a gallon, up to 10.4 gallons from the pump.

After all the dust settles and I start the car, the gas guage only goes up to 9 blocks, not 10.

What's the scoop on this? Real bad idea, do you normally do this, etc.....

Thanks..

[richard schumacher]

Please don't do it. This tends to saturate the vapor canister, which increases emission of gasoline fumes.

[cgraham]

Originally posted by richard schumacher@Mar 5 2006, 02:20 PM
Please don't do it.  This tends to saturate the vapor canister, which increases emission of gasoline fumes.

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Hmmm:

What ambient temperature were you fllling at, Daronspicher?

"After all the dust settles and I start the car, the gas guage only goes up to 9 blocks, not 10."


It sounds like a deformed (shrunk) bladder to me: they lose volume when cold, and it may take the extra weight of more gasoline to expand it. However, because the tank uses a float guage, I would expect it to show full even if contracted.

There is usually a slight lag before the guage reaches 10 bars if you set out to fill the tank. In my warm climate this just means waiting, with Acc. on, and watching the guage to make sure it geets there: so far, it always has after the pump first cicks off.

If the guage shows the tank not to be full, I don't know why you could not have added another bar, without causing any emission issue. ( my '06 has given 70-125 miles _before_ the 1st bar is lost, without any unusual effort to fll it - admittedly in warm S NM.)

c

[eagle33199]

Originally posted by cgraham@Mar 5 2006, 05:36 PM

There is usually a slight lag before the guage reaches 10 bars if you set out to fill the tank. In my warm climate this just means waiting, with Acc. on, and watching the guage to make sure it geets there: so far, it always has after the pump first cicks off.

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So is your car still on while you are pumping gas? for most cars thats a bad idea, but i never thought about the difference with the prius... if the gas engine isn't on, does it matter if the car is on?

[daronspicher]

I'm chicagoland, it was about 35 degrees out when that fill-up happened.

I drove home about 3 miles, parked overnight, then drove to work. I'd say... about 20 or 30 miles on the tank when it finally went to 10 bars full.

About 140 miles on the tank before I lost the first bar. I'm a little over 300 miles and have 7 still showing.. which I think means I have 6.x bars left.

The MFD for the tank is showing 49.9.

All of this info just to see if anyone has any huge red flags for having put that extra 1.5 gallons in after the click-off.

I see the vapor canister comment. I guess I'll have to read up on that thing and see what the deal is.

Thanks for the feedback, it's been an educational and informational 1900 miles thus far.

[cgraham]

Originally posted by daronspicher@Mar 5 2006, 09:40 PM
I'm chicagoland, it was about 35 degrees out when that fill-up happened. 

I drove home about 3 miles, parked overnight, then drove to work.  I'd say... about 20 or 30 miles on the tank when it finally went to 10 bars full.

About 140 miles on the tank before I lost the first bar.  I'm a little over 300 miles and have 7 still showing.. which I think means I have 6.x bars left.

The MFD for the tank is showing 49.9.

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I suspect the temperature dropped overnight, the tank cooled & shrunk and forced the float to full. However I have no experience with such temperatures.

The number of gallons before I lose the 1st bar seems quite variable. I'm surprised you got 140 mi out of it, if I am correct in deducing that your tank was already shrunk by the cold when you filled it. It will be interesting to see how much gas you use to get down to 2 bars.

Everythin I have seen here indicates the gas guage is quite unreliable in telling you what volume you have at any time. One poster said the guage is not even linear. SO I don't think I would ever want to project what milage I had left at 2, 1 or 0 bars!

I have been trying to calibrate my bars against miles travelled. I usually get 20-25 mi for the higher ones, but haven't got to the all-important lower ones yet.

I doubt the results will be very accurate, as the tank volume varies - probably as one travels!


Settig the power switch to Acc is the same as doing so on a conventional vehicle, to hear the radio, while filling, as far as I know.

[Salsawonder]

I have never had a car that was such a challenge to gas up! I have some short trips around La Mesa that drops my mileage down a bit. If I drive further I have better gas mileage.
When I first had the car I overfilled twice but have not had that happen during the last 4 months. I always get all 10 bars back up after a fill-up. The first bar drops anywhere from 80's to 110. I have averaged mid-forties recently in town, upper forties and low 50's on trips. I do live in a fairly nice climate though.
You "Northers" have more challenges than us sunlovers.

[cgraham]

There is another relevant current topic you might want to read:

Ran out of gas after 472 miles

C