Does gasoline evaporate quickly in summer?
2 Answers
In summer, the possibility of gasoline evaporating from a car exposed to the sun is extremely low because the fuel tank cap is sealed with a rubber gasket, and the fuel line is connected to the engine, which is also sealed: 1. Gasoline in a car exposed to the sun will not evaporate from the fuel tank, but it may deteriorate, potentially producing excessive gum and carbon deposits in the intake system, affecting the engine's normal operation; 2. Gasoline is an industrial oil product that is very easy to evaporate. However, gasoline added to a car's fuel tank is generally well-sealed and not prone to evaporation. If the fuel tank's sealing is poor, it may evaporate to some extent; 3. In summer, when temperatures are relatively high, it is recommended not to park the car in direct sunlight, as this can damage the gasoline lines.
I've been driving for ten years, and every summer people ask me if the fuel in the tank has evaporated due to the sun. In fact, gasoline does evaporate more easily when heated, with molecules becoming extremely active at temperatures above 30°C. However, modern vehicles are equipped with a fuel evaporation control system. A charcoal canister is specifically designed between the fuel tank and the engine to capture vaporized gasoline with activated carbon, which is then burned during ignition. I've measured the evaporation rate under normal usage—less than half a cup of cola evaporates from a full tank over two months. When refueling, don't fill it to the brim, as thermal expansion can cause fuel to spill out from the filler neck, which is both wasteful and dangerous. Stopping when the fuel pump clicks off is sufficient. Parking in an underground garage can reduce evaporation compared to leaving the car exposed to direct sunlight.
