Full tank of petrol is bad for your wallet

Full tank of petrol is bad for your wallet


Here is a scenario that happened to us just last week. We asked for a full tank of petrol at the station for our Chevrolet Cruze, which was already 60% full. The attendant put in the pump nozzle and left. The tank was then full and the nozzle “clicked” and stopped pumping at Dhs 39.40 only. So I pull out 40 bucks in cash, ready to hand it over. The attendant came over and started forcefully pumping more petrol into the tank, even as the nozzle clicked several times. This pushed up the bill to Dhs 42. The ironic bit is no one ever receives extra petrol after the first click. Any “extra” being forced in simply flows back into their storage tanks, but your bill still goes up.

According to the U.S. EPA government agency, topping off the tank can result in your paying for petrol that is fed back into the petrol station’s tanks because your car’s tank is full. The gas nozzle automatically clicks off when your tank is full. Modern petrol station pumps are equipped with vapour recovery systems that feed back gasoline vapours into their own tanks to prevent vapours from escaping into the air and contributing to air pollution. Any additional petrol you try to pump into your tank may be drawn into the vapour line and fed back into the station’s storage tanks.

If that weren’t enough reason to not go “full tank,” you need extra room in your petrol tank to allow the petrol to expand. If you top off your tank, the extra petrol may evaporate into your vehicle’s vapour collection system. That system may become fouled and will not work properly causing your vehicle to run poorly and have high gas emissions.

The only reason we topped up was because our 2010 Chevrolet Cruze long-termer does not have a trip computer, so we are having to calculate fuel economy manually by topping it up, resetting the trip meter, driving a certain distance and then topping up again to see how much fuel was burnt over that distance. In our Jeep Grand Cherokee, the way we drive, a topped-up tank causes a stench of petrol every time we take tight turns quickly. Who knows what’s spilling from where.

The real kicker is that petrol stations are damaging their own vapour recovery systems by forcing them in a bid to make a few extra bucks.

You can avoid being overcharged simply by asking for a monetary amount worth of petrol, say Dhs 50 or whatever, which you know to be less than full tank. Or you can ask for a full tank and argue with the attendant not to force the nozzle once it’s done.

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Comments

  1. Oh my… great info. They do this every time i fill petrol in Pathy… i put full tank once a week if it ends up at 90.3…then fuel attendent tries to round of money by pushing it to 91 and he ends up in making it 91.5 and then he will take it 92…so this has been going for 2 years now…

    But in one case i did notice while overtopping, the petrol actual overflowed…not sure whether it was overflow or some petrol fell off as the attendent pulled the nozzle back…

  2. Everybody knows that you always have to specify “Auto stop buddy!” instead of “full tank buddy!”

  3. great info dint know that, i specify how much dhs to put mostly but sometimes i do go for “full tank buddy” cuz nobody told me there was a “auto stop buddy”

  4. Its a must to allow space for the fuel to expand, considerin we r livin in Sahara Continent 😛
    P.S… its gud to re-fill at night, the land breeze helps someways 😉

  5. this solved my greatest mystery and concern ! i always wondered my tank is 60 liter despited having couple of liter pertol left the full tank some time reaches 62-63 liters by force full clicking..now finally i came to know the science…i always though there meter over shows false , great article

  6. Author

    Thanks to Bijoy, owner of the Seat Leon Cupra at the DriveArabia meet, for the tip-off.

  7. I don’t agree. I worked my self at gas stations for over 5 years while my stay in Canada during my MBA. Yes we do have vapour recovery but no way the petrol is getting syphoned back as there is a separate vapour recovery line inside the black hose….and its so small that only vapours enter in it.

    and yes when u see that you have a tank of 60L and you get 62 litre in it you have to know that your fuel pump and fuel gauge inside the tanks sits about 2-4 inches from the top of the inside tank * I am a fun time tree shade mechanic of my own car * so that 2-4 inches depending upon design of each car can give you a full needle while there is still space to fill up the tank further in some car just the funnel pipe to the tank can hold close to 2 litres. and 2-4 inch depth gap inside the tank if you multiply the area is about 2-6 some time upto 8 liters * in american cars the sticker capacity of gas tank as well call it is N + 1 which is e.g. 20 gallon offical + 1 is reserve. The reason they dont count that 1 extra is because they dont want people to be running their cars on empty as with electric fuel pump it dwindles their reliability if you run it real low every time and we do it a lot a petrol is expensive and most people are in habit of pulling up for petrol after you see the yellow light….like in my car the capacity is 72 litres lights come on at about 62 liter and when i go fill it i some time get to 70 liters if its real empty. so no its not going back else people in poor nations like pakistan india would kill if they do that so it doesnt happen

    so please with all due respect i can take this challenge up and prove it wrong.! the writer is just basing his info based on an incident

    • I completely agree with you. I do Dubai Abu Dhabi everyday and this extra 3-4 dirhams after the hose is full for having extra 30-40 kms that i can drive without having to stop daily for gas refill. This means that these few more gas amounts DO STAY in the car, but yes i think sometimes whether this practice might be risky or not.

    • you make no sense.

    • i’ve tried and tested this a dozen times over (both by stopping at auto stop and going past).

      i live in vancouver, bc and occasionally i drive to bellingham, wa (about 70 kms away) to get gas and other things which are cheaper across the border. bellingham gas is about 27%-30% cheaper so it works out to quite a bit of savings by filling the car and four 10 litre cans every time. thats buying about 80 litres of gas at a time.

      i ALWAYS TOP UP past a four/five+ clicks in Blaine to get as much as I can in the car itself. When i get in my car the needle is quite a bit higher than the ‘f’ line. if i leave it at auto stop this does not happen. auto stop leaves the needle exactly at ‘f’. so extra the extra clicks must surely add more gas to the tank.

      also when i make it back into vancouver (70k drive @ 110 km/h) the needle hasnt budged AT ALL. It still shows more than the ‘f’ line. this does not happen if i only fill at the first click. so… again the extra gas i pumped past the auto stop must actually be in the tank.

      if there was ONLY feed back past the auto stop this would not happen. the gas would be exactly the same no matter what and the needle would technically start to dip lower instantly instead of staying higher than the ‘f’ line.

      i dunno about other cars/pumps. but it certainly works in mine and my dads and my friends and my sister etc etc etc regardless of which pump we fill at.

      but that being said.. ive heard that pushing past auto stop does not give good mileage and can be bad for the environment. but i’ve found that it works for me and mostly i cant help it. im a hog for the ‘cheap’ gas across. lol. oh and the drive. gotta love the drive.

  8. no my car user manual says 57 tank + 3 liter for reserve…

    well i guess need more research then…

  9. Author

    I did not base anything on a single incident. It’s what the U.S. EPA says.

  10. anyways this is a new information…lol i always see them clickin again n again pushin 1 or 2 dhs up and i end up givin the remainin coin change as tip…

  11. Fruck that, no more top up. Oh hell no !! Extra fils for my Bebsi 🙂

  12. wat a great info man!!!!!
    keep it up!!!!! bro

  13. So instead of sayin full tank special for example , you can say auto stop special? will they even know what that is?

  14. USEFUL INFORMATION, THANKS TO DRIVE ARABIA

    AS PER MY ACUTE KNOWLEDGE, WE SHOULD NEVER GO TO THE FILLING STATION TO FILL A TANK WHILE THE FUEL TANKER IS THERE TO REFILL THE UNDERGROUND TANKS.

    THIS IS TRUE THAT WE SHOULD NOT GO FOR THE FULL TANK
    ONCE WHILE I USED TO HAVE A DAIHATSU SIRION WHICH CAN HANDLE 40tr. OF PETROL WAS FILLED BY ONE AT EMARAT FILLING STATION IN SHARJAH FOR 63 DHS.

    I LEFT THE CAR AND ASKED THE STAFF TO CALL HIS DUTY MANAGER, SO THE MANAGER CAME AND HE BLAMED ME THAT I AM THE ONE TO SEE CAREFULLY THAT THE ,METER READING IS IN ZERO POSITION, I TOLD HIM THAT IT WAS AT ZERO BUT MY CAR IS FILLED WITH JUST 55 MAXIMUM.

    BUT THE WHOLE DISCUSSION TURNED OUT NOTHING

    ONCE A PETROL STATION STAFF IS TALKIN WITH ONE OF HIS COLLEGE AND AT THE SAME TIME GOING TO FILL PETROL IN MY CAR, SO HE MADE BIG SCRATCH ON THE PETROL LID AND JUST DENIED SAYING THAT IT WAS THERE BEFORE.

    THIS KIND OF ILL BEHAVIOR WILL BE FOUND USUALLY ON MOST OF GAS STATIONS.

    ONCE I REQUESTED TO CLEAN THE WINDSHIELD AND THE GUY OVER THERE REPLIED ME RUDELY SAYING NO TIME AS MORE CARS ARE HERE TO FILL AND NO SUFFICIENT STAFF AVAILABLE, ACTUALLY HE WAS CHIT CHATTING WITH ONE OF HIS OTHER COMPATRIOT

  15. i have discussed this with ppl alot n no1 seems to believe me..

    u r right, nozzle clicks coz the tank is full, otherwise y wud it click!? out here in Abu Dhabi, the attendants only keep fillin up to the point where they cud round of the figure.. eg if the nozzle cicks at, say, Dhs88.43, so they wud keep fillin it up till 89..!!

  16. Nice eye opener, let me add some points which I read somewhere – One should always fill up a tank in the mornings as the fuel in the underground tanks have cooled down during the night. During day time the temperature rises and the fuel inside the tank expands. Remember liquid fuels are measured and sold by volume not weight.

  17. There is no much difference in filling in morning. The expansion of fuel / degree temperature is very negligible. Also note that temperature variation is much less in a buried tank where fuel is stored.

  18. Thanks Mash for the credit (just got back into town now btw hence the late post) – well yeah this is something I’ve read about in many places so it certainly is worth thinking about. There is a reason why pumps stop while filling up so might as well be safe than mess up the car.

    Also the note on filling while a tanker is pumping fuel into the station by nadeem is also something I follow – it supposedly gets the grime in the underground tanks all over the place so best to wait for the sediments to settle before filling up again.

    PS – it’s the Seat Leon FR I drive my friend 🙂

    Take care bro!

  19. lolz i tried auto stop buddy yesterday , the petrol pump guys say what sir ? i said auto stop..then he said auto stop for how many dirhams..
    i said on first click just stop…
    so one first click stopped it was 58 liters and 106.23 fill for supper…the another guy attempted to do click i was out so i said just stop dont dare……
    so i gavem them 106 🙂 the petrol pump guy was bit confused on how to ask me for .23 fills 😀 and my intial aggression on them made them sacre…so finally i am i am getting my cheated money back from them yahoooooo .23 fill to start wtih

  20. Did the same thing today: ” buddy! when it clicks, STOP!! THAT IS IT NO MORE!!” Didn’t work! he still force it down a couple of times!! LOL!! I’d rather give them 5 more bucks as a tip than making rich people richer… But they don’t want that. anyways from now on i will fill in AUH where is cheaper.

  21. It seems the only way to save your fuel and money is by getting out of the vehicle and standing next to the fuel pump till it reaches auto stop. Im not complaining but our local bunk boys will simply nod their heads pretending to have understood what you’ve just asked and still keep forcing fuel into your tank after the fuel pump cuts off at auto stop.

  22. best is tell them to fill for certain money ,u have petrol bunks in all corners ,why u need to fill it full all the time ,u can put in for some money and do it again when the needle goes to half

  23. Better way to save petrol is to go easy on the gas pedal! people like me (with lead food syndhrome) have no chance in saving.

  24. i do not agree cause even after the 1st click my range km goes up as extra petrol is being filled,1 time the guy inserted 4dhs extra and the range jumped

    • Author

      You know the range reading in your car is always wrong, right? My gauge keeps going up for a few seconds even after filling is done.

  25. This seems interesting…
    As per my observations from Bombay & Riyadh, the nozzle to fill the tank goes deep inside and stops filling once the fuel level reached the nozzle tip..
    I believe the nozzle is designed such (long) to leave some room for expansion as brothers here have mentioned..

    These guys top off to the nearest whole number by lifting the nozzle few inches above and filling it again till the Rupee/Riyal value tops off.. In India this extra petrol is very less as we get very little amount of petrol in 1 rupee (125ml) But in Riyadh in we get 2000ml in 1 riyal..
    So the attendant fills almost 1-2 liter extra.. And as u mentioned, I too get the petrol smell sometimes in my car, but upon inspection everything was perfect..

  26. Please explain the laws of Physics that allow fluid to travel up the hose, defying gravity back into the storage tank?
    Do you have to try or does being stupid come naturaly?? I used to manual fill my car and can say for sure it is possible for the fuel to reach the to of the inlet. Also there is no way for fluid to travel back only spill out, by your logic all petrol station should be swimming in petrol!!! Please stop spending so much time at the garage the fumes are melting what little brains you were born with.

  27. Hi guys I hope you can help me, I am a lady and I think I just got cheated to paying way too much for spilled fuel.
    I just put fuel in my car in Dubai and it wasn’t even empty. I probably had a little less than 1/4 of the tank left. I have a Renault Duster and the manual says it takes approximately 50 litres.
    Normally when I fill and the tank is empty, (light just went on) it costs me 65AED.
    Today I was on the phone,while waiting for my petrol attendant and I told him to fill up and when gave him 100AED he did not bring me change.
    I asked for a receipt because I know it is never this much!
    He reluctantly gave me a receipt and said my tank is very full now.
    I said that’s impossible. My car does not take so much!
    The receipt said he put 58 Liters in!! How is this even possible? 8 Liters too much and there was petrol on the floor.
    He said the pump does not have a stopper and then he walked away.
    His manager keeps telling me this is impossible.
    So now I don’t know what to do.
    They will look at surveillance tapes but I feel cheated and I’m pretty sure they wont be able to see the spillage from their cameras as the guy behind me in the queue quickly took my place as I tried to look back.
    Is it possible that the petrol went elsewhere? Back in their pump, or even somewhere else in my car?

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