We all are aware of simple science, in day to day activities that we perform. Talking of solids,liquids and gases which many of us would have studied during early days in school has a lot more to teach when it comes to maintaining vehicles.
FILL FUEL IN THE NIGHT . WHY ?

Filling fuel in your vehicle during the morning is a classic example of liquids expanding on heat. In other words,liquids gets converted to gaseous matter at higher temperatures. So which means density reduces when heat increases . When petrol is such a volatile liquid, during the night time or early mornings when the weather is not so hot , is more dense when compared to mid-day during when the temperatures are a lot higher. So what does this mean , this means a litre of fuel is not actually a litre of fuel during mid-day as density of the fluid is relatively lesser during that period. Hence , as safe practice filling fuel during the night time , late evening or early morning is a lot better and is sure to give you the quantity for which you pay for !.

IJKL