Does gasoline go bad, and is there any way to know if the gas in your mower is still good? Well, knowing the lifespan of the gasoline in your lawn mower will definitely save you from unnecessary downtime and potentially costly repairs. Fortunately, gasoline technology has progressed over the years with the introduction of boi-fuels and additives, helping extend the lifespan of gasoline. But how long does it take for gasoline to go bad? Let’s go over what impacts the lifespan of gasoline and some tips to make gas last longer.
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How Long Does Gas Last?
Gasoline will begin to degrade after 30 days if left unprotected and stored incorrectly. Additionally, environmental conditions can accelerate the chemical processes and degrade fuel even faster.
Why Does Gasoline Go Bad?
Hydrocarbons are what give gasoline the necessary combustibility to start our lawn mower engines. However, these elements degrade and lose their volatility over time, making the gas less combustible. In addition, aerobic and anaerobic bacteria begin to form in the gasoline, adding to the problem. Finally, contact with materials can cause the fuel to oxidize and make it less combustible.
What Makes Gasoline Degrade Faster
Even if you store gasoline in optimal conditions, it will naturally degrade. So, exposing the fuel to factors that accelerate the chemical process will drastically shorten its lifespan. This is why it’s important to be aware of the factors that affect the shelf life of gasoline. Here are some factors you can immediately address to increase how long your gas is good for.
Metal & Oxygen
When gasoline comes into contact with metal and oxygen in your lawn mower, it starts to oxidize. Oxidized gasoline degrades faster and creates a fuel gum, a clear sticky substance that creates problems like clogging the fuel system.
Evaporation
One downside of ethanol fuel is that bio-fuels draw water from the atmosphere during evaporation. As a result, water vapor and condensation accumulate within the fuel and reduce the combustibility.
Heat & Sunlight
The lawn mower engine uses the carburetor jets to vaporize gasoline so that it’s able to ignite. Similarly, when gasoline is warmed through environmental conditions and direct sunlight, it vaporizes and evaporates, causing it to lose its volatility.
Signs of Bad Gas
Once the gasoline starts to degrade, you’ll notice several problems with your lawn mower. If you don’t change the gasoline and allow it to degrade even more, these issues will worsen. Here’s what you could notice when using bad gas in your lawn mower.
- Problems Starting Your Mower
- Lawn Mower Keeps Stalling
- Unstable Idling
- Poor Performance
Tips to Make Gas Last Longer
Use these four simple tips to slow down your gasoline’s degradation process.
Plastic Fuel Container
Use a plastic fuel container to collect gasoline at the gas station and to store gasoline at home. Metal gas cans boost oxidation, causing the gas to begin degrading immediately.
Air-Tight Container
Check that the lawn mower’s fuel tank and the fuel storage container have air-tight seals. This will limit the evaporation process.
Store Small Amounts
Only store gasoline that you will use within 30 days. Storing excess fuel beyond 30 days may accidentally lead you to use bad fuel in your mower and cause avoidable issues.
Storage
Avoid heated areas and direct sunlight when choosing a location to store your lawn mower. Finding a spot in the shade and away from the sun will reduce the evaporation and heating of the gasoline in your lawn mower.
How to Extend the Lifespan of Gasoline
30 days isn’t a very long time, so using a method to extend the lifespan is a great help, especially if you already have fuel in your lawn mower. The simplest solution is to use a fuel stabilizer. Modern stabilizers greatly reduce the chemical processes that cause gas to go bad. For example, a product like STA-BIL Storage Fuel Stabilizer can extend the lifespan of gas for up to 2 years. Also, some stabilizers come with additives that assist in other areas, like stopping ice from forming during winter storage.
How to Test if Gas Has Gone Bad
You can do a simple visual test of the suspicious gasoline against new gasoline. Pour some of the old gas into a clear container and fresh gas into another clear container. Hold them up to the light and compare the colors. If the old gas is brown/yellow, it has oxidized and needs replacing.
Dangers of Using Bad Gas
If you use your mower with bad gas, you might run into a few problems with your lawn mower engine. Unfortunately, bad gas creates fuel gum, which can cause potential harm to various components within your engine’s systems. Here are some of the repairs you may need to do.
Repairs to Fix Problems Caused by Using Bad Gas
- Replacing a fuel filter clogged with fuel gum
- Cleaning fuel line clogged with fuel gum
- Cleaning the carburetor jet & float due to fuel gum
- Cleaning/replacing the lawn mower spark plug
- Cleaning the fuel pump
What is the Best Gas for Lawn Mowers
When you’re going out to get fresh gas for your mower, make sure to get the right one. If you’re unsure, check out my article on the best gas for lawnmowers to learn about the different gas types and which ones you should use, and the ones you shouldn’t.
