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Do you know that there is also a right time to fill petrol and diesel? Yes, there is a time between day and night, when by filling petrol you will get more oil for the same money.
These days a trick is going viral on social media. According to the trick, the right time to fill petrol or diesel is early in the morning or at night. The reason for this has also been explained. According to Viral Reels, the density of fuel increases in cold temperatures, resulting in more oil for the same money.
During the day, fuel expands due to heat and less is available through evaporation. But is it true after all? According to experts, studies and fact check, this is mostly a myth. That means this is a little bit true and a little bit wrong too. Let us tell you in details.
What does science say?
Yes, a liquid like petrol expands and its density decreases as the temperature increases. Whereas in cold it shrinks and its density increases. Theoretically we should get more mass (energy) in the morning or at night because we pay for volume (litres). But this does not happen in practice. Actually, fuel is stored in underground tanks at petrol pumps. These tanks are deep underground, where the soil acts as insulation and the temperature remains almost constant throughout the day. Several studies such as Consumer Reports (US), Financial Express and Indian sources show that the temperature of the tank varies by less than 1 degree Celsius from day to night. Due to such a small change, the difference in volume is negligible. There is a difference of a few milliliters in a full tank which cannot even be measured.
it doesn’t matter much
Even in India, the tanks of petrol pumps are underground, hence there is no impact of external temperature. If we talk about the fear of evaporation, then it is also wrong to say that petrol evaporates due to heat during the day. Modern pumps have sealed nozzles and vapor recovery systems, which prevent evaporation. There is very little loss even in old pumps. The density of petrol in India is set by the government at 730-800 kg/m³. There is a density meter on the pumps, which can be checked. Even if there is an effect of temperature, it is so small that it does not matter. Many fact checks have called it a myth.
Then why is morning or night a better time?
There is a psychological reason for this. Actually, there is less crowd in the morning and work gets done quickly. Sometimes oil is available at discount or low rates at night. But density is of no benefit. If the delivery takes place in very hot or cold weather, there may be a slight difference, but on average it does not happen. Experts advise to refill the oil at any time, the difference is negligible.
