When refueling the most suitable concrete mixer

Due to the large concrete mixer truck fuel consumption, often need to refuel. Often have concrete mixer driver complained noon plus a full tank of fuel, not to call it a day in the evening soon no oil. The same car, the same load, which is why I use the mixer so fast? I said that according to his analysis of the situation, summed up the reasons:
One can avoid the midday sun by the drug, the high temperature of the invasion, partly because gasoline is billing volume rather than weight, thermal expansion and contraction. Gasoline volume at night or early morning is relatively small, the same volume of gasoline may have better quality, it is not easy blistering and volatile, so at night or early morning refueling. Although the vast majority have a underground oil storage depots, petrol is not directly exposed to higher temperatures, the temperature is relatively stable. But in theory, when the hot weather, gasoline or will be expanded slightly when passing through tankers. Especially in the hot summer weather, the outdoor temperature is 37 degrees Celsius at noon, potentially increasing the coefficient of expansion of the gasoline, the owner is also the most suitable for refueling.
So you owners who pay attention, to try to choose at night or early morning when more cost-effective and energy-saving fuel.