Spring is finally here, and the smell of fresh-cut grass is in the air. It’s time to fire up the lawn mower and get your yard looking pristine. But before you pull the cord, you might be wondering: can you use last year’s gas in your lawn mower?
This is a common question, especially for homeowners who store their mowers over the winter months. While it’s tempting to simply pour in the leftover fuel from last season, it’s not always the best idea. This article will explore the potential issues of using old gas in your lawn mower and provide you with the information you need to make a safe and informed decision.
Short Answer: It’s generally not recommended to use gasoline that’s been sitting for more than a few months. Old gas can cause problems with your mower’s engine, leading to performance issues, damage, and even costly repairs.
The Downside of Old Gas
Gasoline, like most fuels, is a volatile substance that deteriorates over time. When exposed to air and heat, it undergoes a process called oxidation, which breaks down the fuel molecules and changes its chemical composition. This process leads to the formation of harmful byproducts called gums and varnishes.
How Old Gas Affects Your Lawn Mower
- Engine Problems: Gums and varnishes can clog fuel lines, fuel filters, and even the carburetor. This can lead to a range of engine issues, including:
- Difficulty Starting: The engine may struggle to start or sputter and die.
- Reduced Power: The mower may lose power and not be able to cut grass effectively.
- Rough Idling: The engine may idle erratically or stall.
- Backfiring: Old gas can contribute to backfiring and other engine misfires.
- Fuel System Damage: Over time, the deposits from old gas can build up and damage fuel system components, leading to costly repairs.
- Storage Issues: Leaving old gas in the tank can lead to corrosion and rust inside the fuel tank and other fuel system parts.
How Long Does Gas Last?
There’s no definitive answer to how long gas will last, as the rate of deterioration depends on several factors:
- Fuel Additives: Some gas blends contain stabilizers that help slow down the oxidation process.
- Storage Conditions: Storing gas in a cool, dark place will help extend its shelf life.
- Exposure to Air: The more air that comes in contact with the gas, the faster it will deteriorate.
However, as a general rule of thumb, gasoline starts to deteriorate after about 3 months and should be replaced after 6 months. After a year, it’s best to discard the old gas and start fresh.
The Risks of Using Old Gas
Using old gas in your lawn mower can come with several risks:
- Engine Damage: As mentioned earlier, old gas can damage fuel system components and lead to costly repairs.
- Reduced Performance: Old gas can cause your lawn mower to lose power and make it difficult to cut grass.
- Environmental Impact: Disposing of old gas improperly can harm the environment.
How to Avoid Using Old Gas
- Use Fresh Gas: The best way to avoid using old gas is to use fresh gas whenever possible.
- Stabilize the Fuel: If you need to store gas for an extended period, consider using a fuel stabilizer. Fuel stabilizers contain additives that help slow down the oxidation process and extend the shelf life of gasoline.
- Empty the Tank: If you won’t be using your lawn mower for several months, it’s best to empty the fuel tank to prevent the gas from going bad.
What to Do With Old Gas?
If you have leftover gas from last season, you’re probably wondering what to do with it. Here are some options:
- Use It in a Small Engine: If the gas is only a few months old, you may be able to use it in a small engine, such as a weed trimmer or leaf blower.
- Donate It: Some local organizations accept gasoline donations for use in their equipment.
- Dispose of It Properly: You can dispose of old gas by taking it to a local hazardous waste disposal facility.
Conclusion
While it may be tempting to use last year’s gas in your lawn mower, it’s generally not a good idea. Old gas can lead to engine problems, damage, and costly repairs. It’s best to use fresh gas or fuel stabilizer to prevent problems. By taking precautions and using the right fuel, you can keep your lawn mower running smoothly and avoid costly issues in the future.
Frequently Asked Questions
Q1: How long can gasoline stay good in a lawn mower?
The shelf life of gasoline depends on several factors, including storage conditions and the presence of stabilizers. Generally, untreated gasoline can degrade significantly within 30 days, especially in hot weather. However, gasoline with added stabilizers can last for several months, potentially up to a year in ideal conditions.
You can extend the life of your gasoline by adding a fuel stabilizer, which prevents the formation of gums and varnishes that can clog fuel lines and damage your mower’s engine. It’s best to use fresh gasoline whenever possible, but if you have older gas, consider adding a stabilizer and running your mower regularly to prevent problems.
Q2: What happens if I use old gas in my lawn mower?
Using old gasoline in your lawn mower can lead to a variety of problems, from engine performance issues to more serious damage. The primary issue is that old gas breaks down, forming gums and varnishes that can clog fuel lines, injectors, and the carburetor. This can cause the engine to sputter, stall, or fail to start.
In severe cases, the buildup of deposits can damage the engine internally, leading to costly repairs or even engine replacement. It’s always a good idea to err on the side of caution and use fresh gas, as it’s much cheaper to prevent problems than to fix them later.
Q3: Can I add fresh gas to old gas?
While it might seem like a good idea, adding fresh gas to old gas is not recommended. Even a small amount of old gas can contaminate the fresh fuel and accelerate the degradation process. It’s best to simply use up the old gas in a small engine, like a weed trimmer or leaf blower, or dispose of it properly.
If you’re in doubt, it’s always better to play it safe and use fresh gas. You can use a fuel stabilizer in your fresh gas to extend its lifespan and avoid the need to use old fuel.
Q4: How can I tell if my gas is bad?
While it can be hard to tell by smell or sight alone, there are some clues that indicate your gasoline might be bad. If the gas is older than a few months, especially if it hasn’t been treated with a stabilizer, it’s likely to have deteriorated.
Other signs include a change in color (gasoline should be clear or slightly yellow), a strong smell of varnish, or a gummy residue in the fuel tank. If you see any of these signs, it’s best to discard the gas and start fresh.
Q5: How do I safely dispose of old gas?
Disposing of old gas responsibly is crucial to protect the environment. You should never pour it down the drain or on the ground. Instead, contact your local hazardous waste disposal facility or a recycling center to inquire about their process for accepting old gas.
Many auto parts stores or gas stations also accept old gas for proper disposal. Follow the instructions of your local facility and ensure you dispose of the gas safely and legally.
Q6: What are the benefits of using fresh gasoline?
Using fresh gasoline in your lawn mower offers numerous benefits. Firstly, it ensures optimal engine performance, preventing issues like sputtering, stalling, or poor acceleration. Fresh gas also reduces the risk of damage to fuel lines, injectors, and the carburetor, saving you from costly repairs.
Additionally, fresh gasoline burns more efficiently, resulting in better fuel economy and fewer emissions. It’s a simple step that can make a significant difference in the health of your lawn mower and the environment.
Q7: Is there anything else I can do to keep my lawn mower running smoothly?
Besides using fresh gas, there are several other ways to maintain the health of your lawn mower. Regularly check and clean the air filter, spark plug, and fuel lines.
Ensure the engine oil is at the correct level and change it regularly as recommended by the manufacturer. Keep the mower deck clean and free of debris, and properly store the mower during the off-season to prevent rust and corrosion. These simple steps will help extend the life of your lawn mower and keep it running smoothly.