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More fuel than tank capacity

Discussion in 'Prius v Fuel Economy' started by ricomtl, Sep 14, 2015.

  1. ricomtl

    ricomtl Member

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    I tried searching before posting and did not see similar threads, so sorry if this has been covered in the past.

    I'm at my 3rd fill up (4th including the 1st by the dealer). I filled up twice recently when I still had 2 bars on the fuel indicator with approx. 50-75miles left before empty.

    How is it possible that I managed to put nearly 48L/12.7G worth of gas while the tank capacity is 45L/11.9G? It even felt like there was still room for more as it didn't overflow/spill.

    On my previous car, I was never able to beyond the tank's capacity... is this something normal for Toyota or the Prius v model?
     
  2. fuzzy1

    fuzzy1 Senior Member

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    Is the pump MPG calculation similar to the car's displayed MPG?
    Is there any chance to measurement fraud at the pump?
     
    #2 fuzzy1, Sep 14, 2015
    Last edited: Sep 14, 2015
  3. ricomtl

    ricomtl Member

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    It happened at 2 different gas station in different cities which I've used in the past and never noticed anything abnormal.

    Yesterday when I filled up, my in-car tank average displayed 5.4L/100km (43.5mpg) while Fuelly gave me 6.2L/100km (37.9mpg). The first fill up where I had the same issue, the car displayed 6.4L/100km (36.8mpg) and Fuelly gave me 8.3L/100km (28.3mpg).

    I'm really scratching my head here.
     
    #3 ricomtl, Sep 14, 2015
    Last edited: Sep 14, 2015
  4. cyclopathic

    cyclopathic Senior Member

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    I think it may be time to report pump operator(s) to state commissioner.
     
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  5. Beachbummm

    Beachbummm Senior Member

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    maybe the car is set for US gallons not Imperial gallons..
     
  6. ricomtl

    ricomtl Member

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    my car is set in liters (I'm in Canada) - I just converted the #'s here using US gallons as I know people here are more familiar with that system.
     
  7. JimN

    JimN Let the games begin!

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    You pumped 48 liters into the tank with two bars remaining?

    If the automatic shutoff has a different setting or pumping further into the neck could account for some of it.

    Average this tank and the next to see if they offset. You should have a very low number on this one and a very high one on the next. If together they are average then I'd chalk it up to "fuelling error". If the combined average is abnormal I would suspect the pump.
     
  8. ricomtl

    ricomtl Member

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    If you check my Fuelly badge in my signature, you'll see the actual #'s. The 1st one managed to take in more fuel than the tank capacity which resulted in a huge discrepancy between car MPG display vs Fuelly manually calculated. The 2nd tank actually matched exactly the car's MPG and Fuelly. The 3rd tank again took more fuel than tank capacity... so I'll only know when I tank for the 4th time if there's another huge discrepancy. Perhaps I was quite unlucky and ended on bad pumps twice.

    I'll continue monitoring this closely. It just so happens I was traveling and went to these 2 different pumps for my fill ups. Otherwise, when in the city, I consistently use the same pumps.
     
  9. cyclopathic

    cyclopathic Senior Member

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    You usually get 2-3mi less than indicated on Fuelly. Any chance car was tilted to pass side and/or nose pointed down? That makes the difference. It is also possible that your fuel meter is off, so what you think is 2 bar is actually less.
     
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  10. Beachbummm

    Beachbummm Senior Member

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    top it off go 200 miles top it off again at the same pump and time of day and see if the mount of fuel used is close, if it is your fine..
    I fill my gen 2 and get 140 to 160 miles before it goes below full, full to half is 40 to 50 miles, 300 miles shows 1 bar but the on board computer says im getting 44 to 47 mpg so I should be well over 400 miles before empty..I just top off every 300 to be safe
     
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  11. Mendel Leisk

    Mendel Leisk Senior Member

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    I think there's a clue in the discrepancy between displayed and calculated litres per 100 kms. If for example my displayed is 4.6 calculated is almost invariably 4.9.

    Another possibility: are you really running it low, then filling to the neck? That's a game with no winners, and the possibility of spillage.
     
  12. ricomtl

    ricomtl Member

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    2 bars left on the fuel indicator on both occasions. I don't think that's running it low and the low fuel light had not even lit up.
     
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  13. cyclopathic

    cyclopathic Senior Member

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    Another trick: when you fill tank put handle at 90deg at 3 o'clock. That allows more consistent fill and no need for topping off.
     
  14. ricomtl

    ricomtl Member

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    So from what I gather - no one here has ever managed to put more fuel than the tank's capacity! Interesting.

    I can only assume I landed on 2 fraudulent pumps.

    Thanks for the input guys.
     
  15. rdgrimes

    rdgrimes Senior Member

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    The fuel gauge bars represent a range of capacity. So 2 bars (pips) can mean anything from 1.5-3 gal remaining. Not reliable by any means for predicting MPG or even how much gas it should take.
     
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  16. Mendel Leisk

    Mendel Leisk Senior Member

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    It is very strange: 2 pips left and you can fill more than specd capacity. I believe too it's very difficult if not impossible to siphon from modem cars.
     
  17. fuzzy1

    fuzzy1 Senior Member

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    People have put more fuel in than the tank's rated capacity on other Prii, but it takes several things: run the fuel gauge down well into the last (flashing) pip; fill the tank into the filler neck, above the normal automatic cut-off point; and possibly have the car tilted significantly while filling. Absent at least two of those factors, you shouldn't be getting that much fuel in.
     
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  18. Tideland Prius

    Tideland Prius Moderator of the North
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    People have put more than the capacity but that's in Japan - they tilted the car with the rear higher than the front, a filed right up to the spout so that they can see the fuel. The neck accounts for a litre or two I think. I can't remember exactly and it's for the regular Prius Liftback and not the v.

    Also, with 2 bars left, you should not be able to fill 48L, let alone anything above 40 litres. At the low fuel light (so the last pip is blinking), you have 10 litres left, so if you refuel soon after the light comes on, the pump should stop around 35 litres.

    With 2 bars left, you're pumping around 32 litres, maybe. It seems really suspicious. You should report it to a Consumer Watchdog and let them take a look. Take note of the pump number and which gas station. Alternatively, you can buy/borrow a jerry can of a known capacity (e.g. 5 litres) and pump 5 litres in and see what the pump says.
     
  19. ricomtl

    ricomtl Member

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    Great input. I'm glad I've came here to validate this... I knew something was odd. It's just unfortunate that I landed on these 2 pumps which are skewing my MPG's. I was so excited to get a hybrid and so far, 36 mpg isn't that impressive! Hopefully it will normalize as I start using my regular pumps nearby my house.
     
  20. Tideland Prius

    Tideland Prius Moderator of the North
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    No. I got 38mpg on a tank when most of the tank was spent at -30°C and one morning, it was at -46°C, so yeah 36mpg in the summer is odd. If you're driving short trips in the city, an average of 6.0L/100km for the Prius v is pretty good. It's rated at 5.3L/100km city, 5.8L/100km highway and 5.6L/100km combined. Of course, once you can stretch its legs and do suburban driving (50-60km/h limits with fewer lights and you're actually moving), you can get it down to 5.3L/100km.

    Heck with a warm engine, I got 4.7L/100km on a short trip that included highway driving around Toyota HQ in Torrance.
     
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