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.
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…
Everybody knows that you always have to specify “Auto stop buddy!” instead of “full tank buddy!”
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”
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 😉
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
Mashfique Hussain Chowdhury
Thanks to Bijoy, owner of the Seat Leon Cupra at the DriveArabia meet, for the tip-off.
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