Gasoline doesn’t expire like milk does, which makes it hard to determine how long the fuel will last.
However, gasoline does go bad fairly rapidly, and age will undoubtedly have an effect on gasoline efficiency. How fast can gasoline go bad, and how long can you store it in your gas tank, or in a gas canister?
In this article, I examine how gasoline lasts, and also consider ways to keep gasoline fresher for longer. Let’s get to it!
How Long Will Gasoline Last?
On average, gasoline lasts and can be stored for ~8 months in a closed sealed container, and 3 to 6 months in your gas tank. Diesel can last twice as long, ranging from 6 to 12 months in the tank.
ExxonMobil suggests gasoline in a sealed container will last about 6 months. Anything beyond this can cause oxidization and degradation, preventing the fuel from combusting.
ExxonMobil also suggests gasoline be used in a vehicle within a month after it was pumped, but gasoline will last anywhere from 3 to 5 months in your fuel tank.
If you have a diesel engine, you have between 6 and 12 months if the conditions are appropriate.
The greatest challenge is determining how old the gas is when you fill up your gasoline tank. It could have been sitting on that fuel station for a month. You also have no concrete idea how long it was stored at the refinery before it was brought to your fuel station.
How to Tell if Gas is Bad?
Gas stored in a container is easy to diagnose. When gas gets old, it’s appearance will change. If the gas container looks darker than normal, and seems to have a sour smell, it is time to toss it.
Gas in the engine is harder to detect, but you could tell if the gas is old simply by how the vehicle runs. As gas ages, the properties and composition of the gas changes.
It will be harder for the engine to process this fuel, and you will notice a rougher idle, and potentially stalling during acceleration. You might even have trouble starting the engine at all.
In some cases, the Check Engine Light can come on. If you have to clear this error, you must have the gas removed from the vehicle before you wreck the motor and the components around it.
A bad gasoline can also cause blockages in the fuel system. Even ethanol fuel can carry in more water vapor and the longer it sits, the more corrosion that develops.
Methods to Avoid Fuel From Going Bad
#1. Buy Only What You Need.
If you are not going to use a whole tank of fuel, why buy it? However, a full tank does limit water condensation and will last longer. It is best to try to fill up your tank every time and use it until quarter or half full before refilling.
Also, don’t top off the tank (unless you are requesting a full tank). The topping off action can harm the vapor recovery system.
#2. Go to Popular Stations.
You do not want to wait in a long line. However, you want to select a busy station. When you select a station with a regular flow of fuel coming into the station, you know the fuel is fresh.
If you want to save time, go at an off hour. This will still allow you access to fresh gas without the long lines.
You can use these stations as quality gas stations.
#3. Make Sure the Gas Cap is Finger Tight.
The gas cap is designed to keep contaminants and water out of your fuel system. If the gas cap is cracked or missing, you have left the fuel system unprotected.
A bad gas cap can also make your Check Engine Light come on as well. Fortunately, gas caps don’t cost more than a few dollars, and they install in minutes.
#4. Add a Fuel Stabilizer.
If you plan on placing your car in storage, you will want to add a high-quality fuel stabilizer to your tank. These additives may also help after the fact when the fuel is starting to turn bad.
To use a fuel stabilizer, fill the gas tank and put the contents in the tank. Drive the vehicle for approximately 10 minutes, so it circulates through the fuel system. A good fuel stabilizer can prolong the life of the gasoline, up to a year.
How to Dispose of Old Gas
First, you should work with your local hazardous waste disposal center or your local government agency to assess where the used gas should go. When you drop-off your gasoline at the proper facility, make sure you take it in an approved and labeled container.
Remember, it is illegal to dumped gasoline on the ground or down a drain. You should not put it in your garbage containers either. If you improperly dispose of gasoline, you could start a fire or contaminate the ground water.