Will gasoline evaporate if a car is left unused for a long time?
2 Answers
Gasoline will evaporate if a car is left unused for a long time. Between the engine's intake manifold and the fuel tank, in addition to the main fuel supply line, there is also a branch line equipped with a carbon canister. When the engine is not running, the fuel tank generates relatively high pressure due to the evaporation characteristics of gasoline. Without a carbon canister, these evaporated gasoline vapors would be released into the atmosphere through the fuel tank vent. Expansion: After installing a carbon canister, the activated carbon inside will promptly adsorb these gasoline vapors, maintaining a certain balance between the internal pressure and atmospheric pressure, thereby preventing most of the vapors from remaining in the system.
My personal experience has taught me that leaving a car unused for extended periods can indeed lead to gasoline evaporation. I remember that time when I didn't drive my car for over half a year due to a business trip—when I returned, the fuel gauge had dropped significantly. This happens because gasoline is inherently volatile, and modern fuel tanks are designed with ventilation to prevent excessive pressure, which unfortunately also allows some vapor to escape. Evaporation accelerates in high temperatures, especially noticeable when parking under the summer sun. Over time, not only does the fuel level decrease, but it can also cause issues like fuel pump overheating or carbon buildup, affecting the next startup. Since then, I've made it a habit to start the engine and let it run for a while every week or two, even if I'm not driving, or to add fuel stabilizers to maintain fuel quality. Additionally, parking in shaded areas can slow down evaporation. Don't overlook these small details in car maintenance.
