Shouldn't You Fill Up the Gas Tank Completely?
2 Answers
You should not fill up the gas tank completely. Here are the hazards of overfilling the gas tank: 1. Increased fuel consumption: A full tank increases the vehicle's weight, leading to higher fuel consumption. 2. Damage to the charcoal canister: When the car is bumpy, fuel can easily enter the charcoal canister. The impurities in the fuel can clog the canister's filter, affecting the air-fuel mixture ratio in the intake manifold. 3. Fuel overflow: Gasoline expands when heated. Although the tank has a charcoal canister to absorb vapors, overfilling can still cause fuel to overflow. 4. Insufficient fuel supply: Overfilling can block the tank's vent, creating negative pressure inside the tank, which may result in insufficient fuel supply to the engine.
I've been driving for over a decade and never insist on filling the tank completely. The fuel tank design is quite clever, always leaving some space for gasoline expansion and contraction due to temperature changes. Especially on hot days, overfilling can cause gasoline to expand and potentially leak out through the vent, leaving you smelling fuel and worrying about fire hazards from leaks. What's more troublesome is the charcoal canister system, which collects fuel vapors to reduce pollution. If the canister gets flooded with fuel, it can clog and malfunction, costing hundreds to repair. I usually recommend filling up to three-quarters or stopping when the pump clicks off—it's safer and more convenient. Maintaining a reasonable fuel level long-term also reduces vehicle weight, saving a bit of fuel per 100 kilometers, which adds up to significant savings over time. Regularly check the fuel cap's seal to prevent vapor leaks and keep your car's fuel system healthy.
