hi, my friend told me the other day that it makes more sense to fill petrol in your car in the night instead of in the day. he says, that since its generally cooler in the night, the volume of petrol you get is more than what you would get if it were daytime instead, since its warmer. so u get slightly more fuel and a better mileage. my take is this : whether day or night, the amount of petrol(moles) you fill in your car doesnt change. so it doesnt make any difference. what makes more sense?