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How did I get 14 gallons of gas in my 13-gallon tank?

Car talkers,



Today (admittedly sitting on empty) I filled up my 13.2-gallon gas tank at a station I have visited before. After filling it up to the very top, I noticed the gas pump meter indicated that I had put 13.98 gallons of gas in the tank.



So…hrmmmm…do you think the gas station is cheating its customers, or is it possible that my gas tank actually can hold more than 13.2 gallons? (The owner’s manual says the capacity is 13.2 gallons, and I’ve never noticed filling up beyond that in the past…)



My car is a 1997 Subaru Impreza.



Thanks!

If you filled the tank yesterday (black Friday) they were using smaller gallons. It made those black Friday discounts seem like a good deal.

Twotone

There will be a certification sticker on the pump for the agency responsible for calibrating the pumps. I believe this agency is different from state to state (someone correct me if I’m wrong). There should be a phone number you can call to file a complaint and have the pump calibration checked and corrected if necessary. You may or may not be entitled to compensation for the inaccuracy, if one is found. If your tank was that empty, the car probably wouldn’t run.

If you take a look at your owner's manual, likely it will tell you to stop filling when the pump shuts off the first time.   Not doing so can cause a problem preventing you to totally fill the tank, so you may overfill or underfill the tank.

The owners manual may state the tank holds 13.2 but this is never exact and this would not include the fuel in the filler pipe. What was the outside air temp while filling up? I ask since this was a secret trick of an old Nascar star Smokey Yunick until it was banned. You can get more gas in a tank using chilled fuel, a small amount, but more.

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While there is a slight chance you were cheated by a gas station, most pumps are checked for accuracy. More likely is you ran on “super empty” and are lucky you made it to a gas station at all. The capacity listed in the manual doesn’t account for the filler neck.

Do you like living dangerously in general?

Thanks for the responses so far!

UncleTurbo: No, I don’t always live so dangerously. Just trying to keep things interesting today, I suppose. :slight_smile:

meaneyedcatz: It was in the lower 40s when I filled up the car earlier.

The “official” capacity is a nominal amount and if parked on a slight incline favoring over filling an additional gallon is not a great deal of extra gas. If the tank is 4’ x 3’ an additional gallon might be not be even 1/2" more fuel.

I agree. Every car I ever had would take more gas than the stated capacity. Nothing wrong there.

Sounds pretty normal. When I almost ran out of gas with my Bronco (it was sputtering and died right as a I rolled up to the pump) I was able to get a little over 34 gallons into a supposedly 32 gallon tank.

I’m not following this. 13.2 gallons should be 13.2 gallons, regardless of the temperature, and regardless of whether it might expand into another volume at a different temperature.

Geez…i wonder how much the fill tube holds

Simple answer is you filled the tank as well as the filler neck. Keep doing this and expect costly Evap. emissions repair in the near future.

Possibly some brands may be sensitive to overfilling but I have often “Packed” my GM car tank when on a long trip at a place with a good gas price knowing that where I was going, prices were higher. Never had a problem.

What do you mean by “to the very top”? Did you continue to fill after the pump shut off the first time?

I just put 14.4 gallons in my 13.2 gallon tank. 2003 Corolla. Scratching my head and did a search to find this thread. I am not alone I see

Did you ‘top off’, or quit at the first click?

2 things 1. Why did you let it get that low on fuel 2. You have a really full tank now so why do you care .

It’s elementary, your tank was beyond empty and now it’s beyond full.

Where did all these guys go in the last ten years?

At any rate don’t worry about it. Every state has their version of a Weights and Measures department. The go around with calibrated tanks and weights and check the actual amounts being weighed or dispensed. Then they certify the pumps or scales or red line them. Highly unlikely the pump is in error.

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