Do you have a car in your garage or storage facility that you haven’t taken for a drive in a while?
Maybe it’s a vintage automobile, a relative’s beloved convertible, or a broken-down fixer-upper you’ve been meaning to restore (but has sat unused for months, years even).
If so, you might wonder if the gas stored in this inactive vehicle’s tank is still usable.
Gasoline may have a shorter shelf life than you think.
Understanding the factors that affect gas longevity, as well as learning the tell-tale signs of bad fuel, can help you dodge engine troubles and costly repairs.
With basic knowledge of how long gas really lasts, you’ll know if your gas has gone bad (and whether or not your vehicle is safe to drive if it’s had gas in the tank for several months to several years).
Fresh Fuel: Factors to Consider for Gasoline Lifespan
How long gas stays “good” in your car comes down to a few factors, such as:
- The type of gas you used
- Storage conditions
- The temperature fluctuations the car has been exposed to
All of these things influence the shelf life of gas. But how?
Type of Gasoline
There are two main types of gasoline sold for your car’s tank: pure gasoline and ethanol-blended gasoline. Pure gasoline has an extended shelf life–but maybe not as extended as you think.
Ethanol-free gas can last 3-6 months because it doesn’t absorb water or humidity. And that’s what helps prevent predicaments like moisture contamination and fuel separation.
Ethanol-blended gas is great for enhancing fuel performance, but ethanol is known for attracting water molecules from the atmosphere, translating to a storage shelf life of about three months.
Storage Conditions
An ideal environment for gasoline is a securely sealed container in a cool, dry, and low-oxygen setting.
Storing in sealed containers prevents the evaporation of volatile compounds and reduces the risk of contamination. A cool, dry environment also minimizes the chances of water contamination and corrosion of the fuel system components.
Temperature Fluctuations
Severe temperature fluctuations can also significantly impact the lifespan of gasoline. Storing gas during periods of extreme temperature fluctuations (the transition from summer to winter) can lead to degradation. In the same way, extended exposure to extreme hot or extreme cold can make gasoline spoil faster.
But here’s another potential surprise related to weather – did you know that unique gas blends are produced in the summer and the winter? And for good reason. Summer gasoline contains heavier hydrocarbons. Winter fuel comprises lighter hydrocarbons, which evaporate more quickly. For this reason,
If you head to the gas station in the summer and use this stored gasoline to fuel your winter ride, you may start to have engine trouble.
Identifying Bad Gasoline in Your Car’s Gas Tank
If you have old gas in your car that you think may have gone bad, you’ll want to check the following:
- The smell
- The color
- The consistency
Fresh gas has a distinct and strong odor, while bad fuel emits a sour or stale smell. If it smells off, don’t ignore it. Take a closer look; otherwise, you might notice that your check engine light flip on unexpectedly.
Another way to identify bad fuel is by examining its color and consistency. Fresh gas typically has a clearer, amber hue, while bad gas is darker or muddier, with colors ranging from orange to dark red or brown.
Over time, the consistency of gas can become thicker due to the evaporation of volatile compounds.
The Impact of Old Fuel on Your Car’s Engine
After a few months of letting your car sit idle, you may have experienced some or all of the following issues:
- Rough idling
- Difficulty starting
- Misfires
- Stalling while driving
These issues can be attributed to the gummed-up deposits that lead to blocked fuel injectors, fuel lines, and carburetors.
That’s because old fuel can form deposits that cause obstructions. In addition, old gas may contain moisture, which can cause corrosion of the fuel system components.
Extending the Shelf Life of Gasoline in Your Car
If it wasn’t clear before, it certainly is now. Using fresh gasoline in your car is considered the best practice. However, there are ways to extend the lifespan of the gas in your car, should you need to store your vehicle or leave it unattended for extended periods of time.
Using Fuel Stabilizers
Fuel stabilizers are petroleum-based additives that can be added to gasoline to slow the oxidation and evaporation processes. Using fuel-stabilized gasoline can effectively reduce the rate these chemical reactions occur, chemical reactions that lead to gasoline degradation.
To use a fuel stabilizer, simply add the recommended amount to your gas tank and drive your car for a short period to ensure the additive circulates throughout the fuel system.
Proper Storage Techniques
Proper storage techniques play a significant role in extending gasoline’s shelf life. Keeping the gas tank full can help reduce the amount of air in the tank, minimizing the chances of moisture entering the system. Additionally, storing your car in a cool, dry environment can further prevent moisture contamination and corrosion.
Observe Good Driving Habits
Your driving habits can also influence the longevity of gasoline in your car’s fuel tank. Regularly driving your car can help prevent gas from degrading through the power of circulation. Note that extended periods of inactivity can deteriorate gas quality.
Allowing your car to remain idle for prolonged periods, driving aggressively, and engaging in frequent short trips or stop-and-go traffic can all negatively impact gasoline shelf life.
Source: Pixabay
How to Dispose of Old Gasoline Safely
Contact your local waste management or fire department for approved disposal sites of old gasoline. These will include Household Hazardous Waste Facilities or local hazardous waste disposal centers.
These facilities are equipped to handle old gas and ensure its safe disposal, preventing potential environmental and safety hazards. Do not throw old gas in the trash.
Final Thoughts
So, how long can gas sit in a car safely? The answer is about 3–6 months, and that’s if you also abide by the safety guidelines. The chemical properties of gas effectively cap its shelf life.
It may seem like a good idea to funnel gas into a storage container and save it for later in the year when prices hit record highs. But it’s not a wise choice when considering the average shelf life of stored gasoline.
The good news is that we’re largely in control of how we treat our cars–a lot of that involves proper car storage when traveling, relocating, or decluttering.
Most gasoline will stay fresh for a few months if we properly store our cars when not in use. If you don’t have access to a temperature-controlled home garage, finding an alternative storage option is a must.
Luckily, there are options like Neighbor, which can help you find a person near you with extra storage space for you to park your ride.
Frequently Asked Questions
Does Gas Sitting in a Car Go Bad? How Long Does Gas Really Last?
Yes, allowing gas to sit idle in a car’s fuel tank leads it to degrade within a few months. Regular gasoline can last 3–6 months.
Can I Mix Old Gas With New Gas?
Mixing old and new gas should be avoided, as this will reduce its combustibility, leading to possible sputtering issues.
Can I Put Old Gas From a Plastic Container in My Gas Tank?
Even old gas from a sealed container will, eventually, go bad. While it may suffice for a lawnmower or snowblower, it’s best to keep bad fuel out of your vehicle’s tank.
