filling up with petrol

[theleeroy55]

I heard a rumour ages ago that it is more economical to fill up your car with petrol at night time?

is this rubbish or is it true?

please explain your answer

[Ethel]

It is true!

Petrol pumps are calibrated by volume, so fill up at night when it�s cold and you get a miniscule bit extra. This is also a reason not to overfill the car after the nozzle clunks, as any excess may go out of the overflow and be wasted.

http://www.moneysavingexpert.com/travel/cheape r-fuel

[NORMANTHEDOG]

the old wifes tales are the best.

[Toureman]

True Norman,

There is a certain amount of energy in 1 litre of petrol, can anyone explain how this energy miraculously grows at night?

[fountain]

No, there is a certain amount of energy in 1 kg of petrol. Depending on the temperature this 1 kg will take up more or less space. So you can fit a greater mass of petrol in the tank when it's cold.

[Panic Button]

But the fuel is stored underground, where the temperature is relatively constant.

I think you will get a greater effect by standing there shaking the nozzle for a minute to get the last few drips out.