The gasoline in your car began life (for lack of a better term) some 360 million years ago. This was long before the first dinosaurs roamed the earth; Despite the popular image of the concept car being “fueled with bangs” t-rexIt’s actually ancient algae and plankton. Considering how long it’s been around for now, we feel particularly unlucky to find it so close to its expiration date.
How long does it take for gasoline to expire?
That’s right: while post-apocalyptic visions of the future such as The last of us or Mad Max Everything seems to happen in worlds where gas that is years or even decades old is usable and valuable, and the reality is likely to involve less “hopping in an abandoned Chevy and doing a quick spin” and more “trying.” Run the engine while inhaling one of the most disgusting smells you have ever smelled.
“Gas Do It has a shelf life,” Matt Crisara confirmed in a recent article for Popular Mechanics. “If left dormant in your car’s tank, it could expire in as little as four weeks.”
With proper storage, this can be extended: “You can expect three to six months with fuel that’s been stored in water vats – in the right conditions,” Crisara explained, while “fuel stabilizers can increase shelf life anywhere between a month to Three years under optimal conditions.
Why does gasoline spoil?
To understand the different ways your fuel can go bad, we first need to look at what gasoline actually is. East – and it’s not a simple task.
The stuff you pump into your car’s gas tank is a very different substance than the crude oil that was extracted from the earth hundreds of millions of years after these algae died. Of course, in its simplest description, it’s the same thing: it’s a mixture of hydrocarbons of different weights, which can be burned to save energy.
However, between this and the gas station, it undergoes some significant changes. The heavier hydrocarbons are stripped, leaving the fuel as a mixture of paraffins (alkanes), olefins (alkenes) and cycloalkanes (naphthenes); Impurities such as sulfur are removed during the refining process; Substances such as ethanol, rust inhibitors and other things designed to improve vehicle performance are added.
These are some of these additives that can cause some kind of problem with residual gas. Ethanol first: It is added to the mixture thanks to its components High octaneAs well as its supposed ability to slight Reducing the carbon footprint of your gas consuming car. However, it is also hydrophilic – likes to bond with water – and this can cause major problems for your car.
“If there is ethanol in your gasoline, it may start to absorb water vapor from the air and put it into the gasoline,” said chemical engineer Richard Stanley. live science. “You don’t want water in your engine because it starts to corrode the system.”
Then there are the olefins. Because hydrocarbons have a double bond between two carbon atoms, these molecules are especially vulnerable to a process called oxidation — they start reacting with oxygen in the air, creating a hard, gum-like substance that can clog your engine.
“Once [the bad gasoline] Entering the pipeline, this gum can break off […] And maybe [it will] It doesn’t completely block the gas line, but it might [it will] James Speight, an independent fuel and environmental consultant and author of more than 100 books and articles on petroleum refining and processing, told Live Science.
“You can almost say that pollution of gas lines is like hardening of the arteries,” he added, likening the blockage of your car to the buildup of cholesterol deposits in the arteries of the body.
This is not the only way that gasoline spoils. Since the fuel is made up only of the lightest hydrocarbons in crude oil—which is usually made up entirely of these chains of 12 carbon atoms or less—leaving it out for too long can actually cause some of these molecules to evaporate. This can be especially problematic if you’re trying to run your car in the summer on the gasoline that’s been in the tank since winter, Speight advised: Oil companies Alteration of hydrocarbon mixtures in gasoline from season to season, to better withstand hot or cold temperatures – and winter fuel is more likely to evaporate than its summer equivalent.
“If you leave the gasoline alone, over time […] “It just doesn’t work the way you think it does,” Stanley told Live Science.
Gasoline, he said, is “like wine.” “Once you take it out of the bottle, it starts to go bad.”
What to do if your gem has expired
So you decide to go on a trip, only to find yourself facing a tank filled with muddy orange dirt that smells like — in Crisara’s words — “an old gym sock soaked in milk and left to rot for years. What do you do?
According to British car service company The RAC, it depends on how full your fuel tank is. “If your tank is full of old fuel (especially old diesel), have it emptied by a garage or mobile service professional,” she says. They advise.
If you use a little less, you may have a cheaper option. “If you doubt that your core [aka gasoline] Or the diesel is old, the best advice is to try refueling with new fuel from a gas station.”
Of course, the best tactic is to store the gas in such a way as to increase its shelf life. “The main enemies of fuel storage are oxygen, water and heat,” William Northrup, a professor of mechanical engineering at the University of Minnesota, told Popular Mechanics. Reduce the impact of those special effects.
To that end, it’s a good idea to store the gas in a fairly full container, Northrup advised: “Some of the volatile components will evaporate,” he explained, “but once the concentration of these volatile components gets high enough in the vapor they no longer want to evaporate because they create an equilibrium.” between the vapor phase and the liquid concentration.
The surrounding environment is more important than the full container. Keep all the gas you store somewhere with a stable temperature and low humidity, advises Northrop—and remember: By its very nature, gasoline is truly Not something you want to treat lightly.
“Remember, benzene is very volatile,” Speight told Live Science. “It’s not worth trying to stock up on bulk. It can only lead to trouble.
He added, “Anything that makes gasoline more volatile than usual affects gasoline,” joking that “on a hot day… [that can include] We look at things the wrong way.