
When refueling at a gas station, after the oil tanker has finished unloading, the oil tank requires a stabilization period of 15 to 20 minutes. During this time, refueling is also not allowed because it takes time for impurities to settle to the bottom of the tank. Since the petroleum products sold at gas stations are highly flammable, volatile, prone to leakage, and can accumulate static electricity, safety is the top priority at gas stations. Here are some precautions for using the fuel tank: Do not wait until the low fuel light comes on to refuel: Before driving, check the fuel gauge and calculate whether you need to refuel based on the distance of your trip and the fuel gauge reading. It’s better to refuel in advance rather than waiting for the low fuel light to come on. The fuel pump is located inside the fuel tank and operates at a high temperature when running continuously. Being submerged in fuel helps to cool it effectively. When the low fuel light comes on, it means the fuel level is below the pump. If you always wait for the light to come on before refueling, it will shorten the lifespan of the fuel pump, and having too little fuel in the tank could even burn out the pump. Choose to refuel in the morning or evening: Generally, temperatures are lower in the early morning and evening, and the vaporization point of gasoline is relatively low, so it’s best to refuel during these times. Gasoline expands with heat and contracts with cold, and it is charged by volume. At lower temperatures, gasoline has a higher density, meaning the mass per unit volume increases, allowing you to get more fuel for the same volume. Avoid filling the tank completely when driving in the city: When driving in urban areas, there’s no need to fill the tank completely. A full tank adds extra weight to the engine, increasing fuel consumption. Since gas stations are readily available in the city, there’s no need to fill up the tank entirely.

I always wait a bit longer to refuel when I see a fuel tanker unloading. That time when I was in a hurry to fill up, the staff told me to wait at least 15 to 20 minutes. This is because when the tanker is filling the underground tanks, it stirs up sediment at the bottom. Refueling immediately could flush these impurities into your fuel tank. Later, I saw a sign they hung that read 'Fuel unloading in progress, pause for 20 minutes.' Now, I make it a habit to check if warning cones are placed near the fuel nozzles or if the staff are wiping the hose connections—that usually means they're finishing up. Here's a little tip: if you notice black smoke from the exhaust pipe after refueling, it's likely that impurities got mixed in earlier.

Taking kids out and encountering a fuel tanker unloading at the gas station can be quite troublesome. Once, a staff member explained that newly injected fuel at lower temperatures generates excessive fuel vapor. While inaccurate pump measurement is one issue, the key concern is the sudden spike in gasoline concentration in the air. I usually time it: after the tanker finishes unloading, wait 15 minutes for vapor stabilization, plus another 10 minutes for staff equipment checks—totaling about half an hour. One time I refueled after just 10+ minutes of waiting, and the car reeked of gasoline for three days. Now I'd rather drive two extra kilometers to another station. Oh, and remember to remind passengers to close windows—inhaling too much fuel vapor can cause dizziness.

Our station's operating procedure is: immediately after the oil tanker completes unloading, the discharge port is sealed, and then the vapor recovery system is activated for 10 minutes of extraction. During this period, the oil storage tank's air pressure must be monitored to ensure a recovery rate of over 95%. After completion, the oil must settle for 7 minutes to allow for proper stratification and stabilization. Only after the entire process is completed will the duty manager remove the warning red flag. If you observe fueling activities immediately after unloading, you can directly report it to the market supervision authorities. Actually, what vehicle owners should pay most attention to is the ground of the gas station. If there are obvious oil stains around the unloading area, it often indicates that such stations cut corners on the required settling and filtration time.

It mainly depends on the size of the oil tank. For small gas stations with 30 cubic meters storage tanks, 15 minutes of settling is sufficient. However, for those large 60 cubic meters tanks along national highways, you need to wait at least 25 minutes or more. The oil quality test report shows that the suspended matter content in gasoline is 7 times higher than usual right after unloading. But now, regular stations are equipped with layered oil extraction pipes that directly draw relatively clean oil from the middle layer of the tank, making it much safer than before. What needs special attention are those small private gas stations. Last time when I helped a friend repair his car and dismantled the fuel tank, half a cup of impurities cleaned out were rust. This definitely indicates insufficient waiting time.

Only after suffering a loss did I learn this rule! Last time at a highway service area, I refueled just five minutes after the oil tanker finished unloading, and within twenty kilometers, the engine started shaking violently. The mechanic extracted two bottles of murky liquid from the fuel tank, saying it was a mixture of water and rust from the bottom of the tank. Now, I always ask about the unloading start time: for a 10,000-liter tanker, unloading takes 45 minutes, and settling requires an additional 15 minutes. Timing it right is the safest approach. A reminder: getting a receipt after refueling is crucial—if the fuel filter gets clogged later, you can claim the cost of fuel system cleaning with the receipt. Here’s a cool fact: gasoline density stratifies during settling, with 93-octane fuel floating on top of 97-octane.


