Yes, off-topic from OP Post, but worth knowing.
As a standard rule, tell the guy at the petrol pump "Auto and Slow, when it stops, don't force more". Reason for this is two-fold.
Auto
1. The guys at the pump often try to fill in more fuel than the tank is capable of, which means the pipe leading to the tank as well. However, most cars (as far as I know) have an overflow valve (aka fuel tank ventilation valve). i.e. too much fuel, and it will flow out. I had this personal experience with my Santro, when filling petrol, the guy filled up too much petrol in the tank and was trying to fill it up more, and there was a puddle forming under my car, thanks to an overflow valve in most cases, we don't spot this because the puddle isn't that big but still.
2. The pump fuel nozzle has a fuel return valve, which is supposed to take back excess fuel and ensures that the tank isn't over filled. If you notice when the man fills the tank manually he has to take the nozzle out a little to "trick" the nozzle into thinking the tank is still empty.
Slow
1 .The fuel return nozzle also takes back fuel vapor. Pumping at high speeds releases more petrol vapors, which your nozzle pulls back in with a vapor recovery system most pumps are outfitted with. This means you could be paying for more petrol than you receive. Pumping at a slower rate releases fewer vapors, which means you’re receiving more of the gas that you paid for.
Disclaimer
This does not mean the petrol station isn't capable of cheating you. I've filled 35 ltr capacity tanks with 40 ltr of petrol multiple times, even with these safeguards in place. I just used a different pump at the same station, and the problem was solved.
