Its caliberating the amount of fuel either used up that day or left in stock. If you go to a Shell bunk you'll find a large notice board with
'Date: current date
Opening Stock
Petrol: xxxxxli Speed: xxxxxli
Diesel: xxxxxli Speed: xxxxxli'

These automated pumps (besides the main computer which also can do that) have a feature to calculate the amount of fuel sold that day and/or left in stock.
The key to start n stop being the trigger of the nozzle.(Why so? I dont know.)

The count starts at 0 and goes on n on and wouldnt stop till the end of the caliberation. It is the attendant who stops it at 100.

^^

1) is it only in shell petrol pumps or everywhere?
2) why is it controlled by nozzle lever.
3) even if it is controlled by nozzle, how does machine knows when to calibrate and when to actually fill petrol, coz there are not two levers..??
4) how are you so sure..?

other members, pour in your comments.

Sorry, but why an attendent's extended hours and livelihood miserly should make me pay for what I dont get? With your theory, every body should be allowed and excused to make mistakes in their job, once in blue moon just because he is human, not a machine. then what about commercial pilots and train drivers? they are human too. right?

Please dont see this as another underpaid-overworked human sad life story. If you want to charity and improve lives, there are ample disabled, abandoned, unable to work people to give suport to.

When I pay rs. 100, I want rs.100 worth of clean, unadulterated fuel for my car/bike. Period.

Unfortunately even I have been scammed, multiple times, using this very trick at the Sanjaynagar BP petrol pump and BEL Road Indian Oil Petrol Pump (bangalore). Both times I said (very clearly) I wanted Rs200/- worth of petrol, both times I got Rs100/- worth of petrol.

To prevent me getting scammed repeatedly, I carry out the following procedure:

1) First I tell the attendant to digitally set Rs200 on the meter

2) Then I ask him whether the zero is set.

3) If he confirms that the zero is set, I open my petrol tank lid, till this time I keep the tank closed no matter how much rush is there or how long the line behind me is.

4) At this point (before opening petrol tank lid) I tell him that he is to put the nozzle in the tank and then let it auto shut. It has happened with me that the attendant refused doing this, saying that they do not have auto shut off in their petrol pump, I have always refused filling up at such stations because that is bull shit. If you can auto set the petrol quantity based on money, then the pump has to have auto shut!

5) If the nozzle auto shuts, then mostly you have received the correct quantity of fuel and not been scammed.

6) Take out wallet and pay in the end.

One advantage is that many times when i asked the person to fill Rs200 petrol, they would fill in Rs198 or Rs199 worth instead of Rs200, by setting up the digital meter this is not possible.

Disadvantage of this method, this takes time. So not only the petrol attendants but the people behind you in the line scream at you. I have personally got into a shouting match/argument because of doing what I do, no less than 5 times! But i still do this, better to hurl a couple of abuses and escape than get scammed of Rs100/- every time you fill petrol.

Also because of this, I never fill petrol from pumps which have analog meters. It has to have a digital meter for me!

This doesn't mean you cannot get scammed from other methods. Once I filled petrol worth Rs200 from Yeshwantpur Flyover Petrol Pump, everything seemed ok but still I got abysmal mileage. The pump was actually horrendous and the petrol reeked of kerosene, obvious adulteration. The bike was running super rough. But i got so low a mileage that I was sure there was meter tampering as well. So I went back with a funnel and a 1 litre bottle and said that my bike had run empty of petrol. The guys refused to give me petrol in the 1L bottle! I asked to see the manager. There was no manager then. Finally they told me to bring a 5L jerry can to get 1L petrol. To cut a long and obvious story short, the pump was not selling the appropriate quantity of petrol. 1L of their petrol was more like 700ml actual Petrol as I could guess by my mileage calculations.

Now I only fill from a Shell petrol pumps simply because of the peace of mind. By having to get up from the bike for each fill, it slows down the process that much more and there is little chance of the attendant scamming you.

@prajnyan why dont you adopt every petrol attendant in the country and spend cash on them lavishly as if they were your own child?
@pulsater Well said good sir!

If possible search that thread for posts between 15april to 18th and you'll find the link.

quite surprisingly, a lot of ppl are telling, what should be done and how to pay more attention, setting zero etc, and a lot of ppl are telling they got looted, but only very few are actually telling, how you can be looted by giving less qty. of fuel.

till now i have come to know only one method and that is by distracting you.

@Prajnyan: I really wanna add in but I guess you got your answer from the above two gentlemen here.

@Princebhaiya: this is where a laptop would help.

@all: I go about 5km up to the Shell bunk despite the BP being next street.
*Speed Shell is the best a man can get.
*Speed Shell is pure for sure.
*Speed Shell is expensive but compensates with the extra mileage that it gives.
*Shell bunks are not crowded
*Shell attendants are polite
*Shell meters are accurate
*Shell attendants dont dare cheat cuz the managers are very strict.
*Shell does free oil checkup
*Shell gives free air fill-up by an attendant
*Shell every now n then gives u contest coupon (though I have never―nothing new―it still makes me feel good)..

Shell hai toh I dont need anything else..

Alright prince here goes my story:

Scam number 1:

I roll into the petrol pump (BP)

There are two attendants, one holding the petrol pipe nozzle and one holding the money bag

They ask, kitna, I say clearly 200

I open my petrol lid, the guy with the nozzle says "ZERO" before I can look up at the meter to confirm zero, the money bag guy says something to distract me (oil change? bhaiya 200 dijiye? Yeh 100cc hai kya? Sir accha colour hai!! or some such bullshit)

The above step happens fast, spontaneously and smoothly

I look to the meter and there is already a 100 there.

I tell him arre bhai ZERO set kiya kya?

Kiya na sir abhi toh aapko bola ZERO

He goes on to fill the tank till meter comes to 200.

I go on to get a mileage of 25 cause the b*&@tards filled in just Rs100 worth of petrol.

Point to be noted: in these cases I never got an opportunity to confirm zero since the money bag guy distracted me.

Another variation of the same method as above (in Indian Oil this time) I clearly remembered I checked "ZERO" then the guy distracted me and by the time I looked back the meter was already at 200 I was like WTF how did that get filled up so fast? There was nothing I could do, checked the tank, only half was filled, got a mileage of 25 again. Till date haven't figured out how they scammed me even after I saw zero on the meter (btw after this I decided to just f*ck it and stick to Shell)

Method number 2:

Everything ok, you fill petrol worth 200 get abysmal mileage of 30-32, which means that you only got half of what you paid for. Hows that possible when I saw everything was ok, they set the meter, zero was fine, filled in to 200 till auto shut. Then where is the problem?

The problem here is that the petrol pump itself is wrongly calibrated. While the pump shows 1L to get filled, actually only around 700ml gets filled in.

These pumps will not allow you to fill petrol in 1L or 2L bottles or 5L cans to the brim. In short they will not allow you to confirm volumes stating safety issues and rules or policy or some such bulls*it

So these are the two ways I have been scammed. Hope you have understood prince! If not, ask away for clarifications.

^^ that is why i am helping for laptop, did you checked the price of laptops in your city (sorry for OT)

but i still didn't got my answers.

one of my friends used to work in one of the companies that make petrol pump dispensers (or whatever they are called), and he used to tell me that they calibrate the machines at the time of installation, and it is the responsibility of machine manufacturer, to calibrate the machines, but petrol pump owners later temper with it a lot.

@Prince I was scammed by Method #2 listed above at Lonavala.

The trick to avoid the scam which happened with ABikerAtHeart is to accept the attendant's apologies but not let him take the nozzle out of the tank. Insist that he goes on and fills initially requested amount of petrol. No resetting midway. In the meantime, NEVER take your eyes off the meter. This has happened with me once before an xBHP ride when I was filling up at 3:45 AM. The attendant took advantage of my sleepiness at that hour, . But since then, I have been attentive, whatever condition I might be in.

The method 1 has scammed me once in the Indian Oil bunk near KRpuram in whitefield road.
But I was to be blamed for this, i was in a hurry because was getting late to office and that 'Mind-reader' attendant took advantage of it by filling 100 instead of 300. I hurriedly told him to fill the remaining 200 and this is when he filled till 200. But he was fiddling with the dispensing machine and i took it for resetting. did not put much attention!
I came out and realized after some distance when the fuel gauge did not come up till expected point and of-course got sad mileage till next fill.
Stopped visiting that bunk there-after!

Replied here,Bhaiya.

@All: incase the day-light robbery has happened to you at Bharat Petroleum, there is an official website where you can complain. Feel free to use it when needed. It really works.

some very good threads on team-bhp--->

The Petrol Pump Story - How Petrol Pumps Operate - Team-BHP

How to ascertain purity of Diesel - Team-BHP

Pumps with fuel density display - Team-BHP

Short Fueling Tricks At Petrol Stations - Team-BHP

Geez! Those guys are really.

Read all of the posts and now I'm calculating the actual no. of times I've been cheated.

The topic is not about adopting your kid here!

All I am saying is until the bunk attendant sets the meter to zero and sets the required amount don't open the fuel cap. If you pay 100 then make sure you get 100. Later don't shout you were scammed.

P.S: Which is why I stick to one fuel bunk and always insist on full tank.