How much difference is there between refueling at noon and at night in summer?
3 Answers
At noon, especially in summer when the temperature is high, the density of gasoline decreases. Therefore, when refueling the same 10 liters of gasoline, the actual amount of fuel added at night will be higher than at noon. It is recommended to refuel at night. Below is more information about gasoline: Gasoline Grades: In China, automotive gasoline comes in two types: leaded and unleaded. Both are graded based on the Research Octane Number (RON), where the number in the gasoline grade represents the octane value. Whether it's leaded or unleaded gasoline, the fuel grades are divided by the Research Octane Number. As long as the fuel grades are the same, their anti-knock properties are identical. Gasoline Characteristics: The important characteristics of gasoline include volatility, stability, anti-knock properties, corrosiveness, and cleanliness.
The difference between refueling at noon and at night in summer mainly comes from the temperature variation of gasoline. Gasoline expands when heated, increasing in volume; it contracts when cooled, becoming denser. During summer when temperatures are high, such as at noon with direct sunlight, ground temperatures can exceed 35°C, causing significant gasoline expansion. Paying the same amount of money would get you slightly less actual gasoline. At night, when temperatures drop to around 25°C, gasoline contracts and becomes denser, meaning the same amount of money buys more actual energy. The specific difference isn't substantial—generally, for every 10°C temperature difference, the fuel volume varies by about 0.6%. If comparing summer noon to night with a 10-15°C difference, the total savings would only be around 1-1.5%. For frequent drivers like me, while this small change may not be noticeable, it can add up to minor savings over time. A more convenient approach is to avoid refueling during peak heat hours—cooler air and fewer cars make it safer and more convenient. Don't go out of your way for this minor difference; prioritize comfort and safety during refueling, as high temperatures can release harmful gases.
As a budget-conscious everyday consumer, I always recommend refueling during the evening or early morning in summer. The temperature is lower at these times, so gasoline doesn't expand as much due to heat, allowing you to get slightly more actual fuel for the same amount paid. This can save you about 1-2% in costs. While the difference might only be a few cents per refill, doing this several times a month can add up to tens of dollars saved over a year—enough for a small purchase. It's best to head out after the evening cools down when traffic is lighter and queues are shorter, saving time and hassle. Don't overthink the details; the key is forming a good habit—filling up during cooler hours and avoiding the midday heat. Fuel dispensers calculate by volume, and in hot weather, gasoline molecules are more active, causing slight expansion and marginally lower energy output. However, the actual difference is negligible. More importantly, choose reputable gas stations to ensure fresh fuel quality.
