How not to get duped at the petrol pump

It’s that time of the month again when Vinnie needs her food. I usually get the tank full at the petrol pumps for three reasons. This avoids extra trips to the pump and it is good for the engine since it results in reduction of the amount of time the level of petrol remains low in the tank. The third reason is to avoid the prospect of a confrontational situation which is explained below.

During initial days in Bangalore, I noticed that my spending on petrol has gone up quite a bit even though the distances covered daily were less than those in Gurgaon. I attributed that to nearly 15% difference in petrol prices and slow moving traffic here. However, with time, it came to notice that there were fluctuations in mileage in Bangalore itself; thousand rupees petrol sometimes lasted 15 days while other times it got over within 10 days.

It must be mentioned here that I am not someone who keeps a notebook on expenses per month and then sits and analyzes them. It’s just that I have a fondness for numbers. I remember quite a few of them and catch any inconsistencies easily. That had led to the blasphemous allegation that I am an extremely caring person just because I never forgot anyone’s B’day. Now I deliberately don’t wish people even if I remember their all sorts of anniversaries. Enough of me, let’s move to the point now.

Since petrol-pumps were the only variables in this situation, it was natural to suspect them. However, even for the same petrol pump, there were considerable variations sometimes. It was turning out to be an intriguing problem. So this one particular time, I decided to be more observant and asked the guy to fill petrol worth Rs.500 instead of the usual Rs.1000. Here is what happened:

I parked my car and got out of it in order to observe the meter closely.

“500”, I said. It’s fun to communicate with as few words as possible.

“Zero Sir”, he pointed to the meter.

“Sir, Cardaa or cashaa?”, another guy approached me. Happens always; get your payment done while the tank is getting filled. Parallel processing; no rocket science here.

I gave him the credit card without uttering a word, which, later I realized, also meant that my attention was diverted.

“Sir! Over. 200.” the first guy pointed to the meter.

“But I asked for 500; you never listen properly. Last time too you did the same thing”, I replied irritatingly.

“Sorry Sir, see zero again”. He went on to fill 300.

Satisfied, I signed the credit card receipt and started the car. Surprisingly enough, the petrol indicator hadn’t moved to half of what it used to move for 1000. “Must be a calibration error”, the forgotten and ignored Instrumentation Engineer in me tried to soothe the rest of me and succeeded for a while.

However, as soon as the car moved, I had the Eureka moment. In the first half of the filling, the full 200 never goes in; there is a button or a trick which when used, directly jumps to that mark. Asking for a credit card, or car wash/paint are tactics to divert the attention. The lost 200 was a smaller part of 1000, but this time when asked for 500, the difference was clearly noticeable.

I got down the car and confronted that guy. Initially he insisted that he heard 200 first. My line was "how come you always hear 200 instead of 500"; not a very persuasive one; all rhetoric and no evidence. There was a deadlock in arguments and it seemed useless to fight with the group. Threats of never visiting their pump didn’t earn any respect either.

Logic came to rescue once again. The car was definitely having some petrol (though not much) before they poured any into the tank. The tank, when empty, used to get filled in around 1700 when you convert currency to liters. The capacity of the petrol tank cannot be disputed. So, if he had already filled in 500 worth of petrol, then he must not be able to fill in worth 1200 more. I asked those guys to go for a full tank and if the amount crosses 1200, then I wouldn’t be paying a single penny. Of course, they didn’t have any comeback for this; that’s the best thing about maths, number of people on the wrong side don’t count.

I had been tricked in such manner more than once at other locations too. When checked with friends, nearly all of them recalled getting duped similarly quite often. Easy money.

So now I always say “full tank”; it cannot be mistaken for 200 or 100. Coming back from Goa I had a thousand rupee note, which I had to dispense off. On my next visit to the pump, I raised 10 fingers and said “Thousand, and don’t play that 200-waala trick with me”. A few extra words, but they were necessary.