Primarily Petroliana Shop Talk Forums Shop Talk Petroliana Forums General Petroliana Discussion How do pumps accurately measure the flow of gasoline?

Yesterday I filled up my car - or I thought that I did. I swiped my card and proceeded to pump. The pump cut off after running a tab of about $32. So far nothing unusual. However, after pulling away I noticed that the gas gage did not register full - in fact it registered very empty (I had let it run very far down.) I gave it some time, but the gage never responded. I went to another station thinking that if it were not full I would be able to pump some more (forget that I was charged $32!!!) At the second station I was only able to "top" it with another $1.10. This was a rental so when I returned it I explained what had happened. I got a call today telling me that they had had to put in 16 gallons!!! How can this happen? Could there have been some sort of vapor lock that created a phantom pump?? I am beyond puzzled. Can anyone shed some light on how this could possibly happen? The rental agency tell me that this vehicle (a 2005/6 Pontiac Gran Prix cannot be siphoned). Thank you.

I believe this question could be better answered by Mr. Goodwrench.
Jack Sim

In Calif. the stations are controled by Department of Weights & Measure [HUGH FINE FOR TAMPERING with a pump after it has been calibraited].
I would send copies of both receipts, highlite the time & gallonage & time you turned the car in.
GOOD LUCK,
db

First off welcome to the site.
This is mainly a site for collectors of vintage gas related items but I can help you out.
I am an automotive instructor with a GM ASEP program to give you an idea of my background.
The 05 Pontiac Grand Prix has a 17.5 gallon fuel tank. As far as the station being faulty on delivery I doubt if they would be as weights and measures check fuel stations fairly often and I see you are from CA. which probably have the closest regulations.
As far as siphoning the fuel may be difficult but putting a fuel transfer tube in the tank with an electric pump we do it every day when replacing fuel pumps. There are two technical sevice bulletions for the 05 Pont regarding a grounding problem and reading empty on an intermittant basis. I personally feel you fueled the car correctly as you went to the second station and it took only a half gallon or so. You do the math. How many gallons did you put in the tank? How big is the tank? Did some employee of the rental agency need gas for their car and saw a great oppurtunity to blame it on a customer. My 2 cents. Hope it helps. Ted

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Ted Pam & Ethyl Roach
Lodi CA.
Looking for Signal, Hancock, Mohawk, Douglas, Gilmore and Richfield
pca-west.org
vintage-logos

[This message has been edited by troach (edited 11-21-2005).]

I would take the advice of everyone that responded. If that does not work go the legal way. But one thing is for sure I would not pay the fee to fill it up. They are trying to rip you off