Maybe you’ve never thought about this question before, but gasoline has an expiration date. In fact, the lifespan of fuel in a car’s tank is much shorter than you might imagine. From the moment it’s dispensed from the pump, gasoline has an expiration date of just four weeks.
Of course, there are a few ways to extend its lifespan (though not for long). When stored in a suitable container, such as a jerry can, gasoline can last anywhere from three to six months. In addition, under ideal conditions, fuel stabilizers can extend their service life by one to three years.
In a post-apocalyptic world, gasoline would become an extremely valuable and scarce resource. That’s why, in movies set on a devastated Earth, survivors tend to fight tooth and nail for fuel.
Why does gasoline have an expiration date?
Gasoline expires or expires because the fuel we pour into the tank of cars is not the same as the fuel extracted from oil fields. After removing some impurities and adding substances such as ethanol and anti-corrosion agents, the fuel becomes more perishable.
“If we have too much ethanol in gasoline, it can pull water vapor out of the air and add it to gasoline,” explains chemical engineer Richard Stanley. “Water in the engine is harmful, because it corrodes the components of the system.”
In addition, substances added to gasoline such as olefins have a major tendency to oxidation. This causes a reaction with the oxygen in the air that ends up forming a sticky substance capable of clogging the vehicle’s engine. There are other ways gasoline can degrade.
The composition of this fuel, made up exclusively of the lighter hydrocarbons of crude oil, makes the evaporation of certain molecules a possibility when stored for long periods of time. For example, if you try to start your car in the summer with gas that’s been in the tank since the winter, this could cause inconvenience.
In fact, oil companies modify gasoline blends depending on the season. Taking into account factors such as the ambient temperature for each time of the year. So, the next time you leave your car idle for too long, remember that gas has an expiration date.