The sun is shining, the birds are singing, and your lawn is crying out for a trim. But before you grab the mower and start buzzing, there’s a question that needs to be answered: what kind of gas should you use? It might seem like a simple question, but the answer is surprisingly nuanced. This article will delve into the world of gasoline, explaining the different types, their pros and cons, and why choosing the right fuel can make a world of difference for your lawn mower. We’ll also explore the importance of proper storage and maintenance to keep your mower running smoothly.
In a nutshell, the best gas for your lawn mower is regular unleaded gasoline with a high octane rating, ideally 87 or higher. However, there are some important factors to consider, such as the age of your mower, the type of engine, and the climate you live in. Let’s explore these in more detail.
Understanding Gasoline and Its Impact on Your Lawn Mower
Gasoline, also known as petrol, is a complex mixture of hydrocarbons that provide the power to fuel internal combustion engines. It is classified by its octane rating, which measures its resistance to knocking or premature detonation. Higher octane gasolines are more resistant to knocking and can handle higher compression ratios in engines.
Here’s how different types of gasoline affect your lawn mower:
1. Regular Unleaded (87 Octane)
This is the most common and affordable type of gasoline, often referred to as “regular” at the pump. It’s suitable for most modern lawn mowers with standard compression engines.
Pros:
- Cost-effective: Regular unleaded is typically the cheapest gasoline available.
- Widely available: It’s readily accessible at most gas stations.
Cons:
- May not be suitable for high-performance engines: Mower engines with higher compression ratios might experience knocking or pinging with regular unleaded.
- Lower energy density: Compared to higher octane gasolines, regular unleaded has a slightly lower energy density, which may result in slightly reduced power output.
2. Mid-Grade Unleaded (89 Octane)
Mid-grade gasoline sits in the middle ground between regular and premium. It offers a slight increase in octane rating, potentially providing more consistent performance in some engines.
Pros:
- Better performance for some engines: It can improve engine performance and reduce knocking in older or high-performance mowers.
- Increased fuel efficiency: In some cases, mid-grade gas may improve fuel efficiency.
Cons:
- Higher cost: Mid-grade gasoline is more expensive than regular unleaded.
- Not necessary for most modern mowers: Modern lawn mowers are designed to run efficiently on regular unleaded.
3. Premium Unleaded (91 Octane or Higher)
Premium gasoline is the highest octane grade available. It offers superior resistance to knocking and is designed for high-performance engines.
Pros:
- Optimal performance for high-compression engines: Premium unleaded is ideal for high-performance mowers or engines with higher compression ratios.
- Improved fuel economy: In some cases, premium gasoline can improve fuel economy.
Cons:
- Most expensive: Premium gasoline is the most expensive type available.
- Not necessary for most lawn mowers: Modern lawn mowers rarely require premium unleaded.
4. Ethanol-Blended Gasoline
Many gasoline blends available today contain ethanol, a biofuel derived from corn. While ethanol can offer environmental benefits, it can also pose challenges for lawn mower engines.
Pros:
- Renewable source: Ethanol is a renewable fuel source that can reduce dependence on fossil fuels.
- Lower emissions: Ethanol blends can reduce greenhouse gas emissions.
Cons:
- Can damage older engines: Ethanol can cause corrosion and damage in older engines that aren’t designed for it.
- Can attract water: Ethanol absorbs water from the air, which can lead to fuel system problems.
Note: If your lawn mower’s engine is older, check the manufacturer’s recommendations for ethanol compatibility. Using ethanol-free gasoline is generally recommended for older mowers.
When to Consider Higher Octane Gasoline
While most modern lawn mowers run smoothly on regular unleaded gasoline, there are some scenarios where using a higher octane fuel might be beneficial:
- Older mowers: If you have an older lawn mower, its engine might have a higher compression ratio that could benefit from the extra knock resistance of mid-grade or premium gasoline.
- High-performance engines: If your lawn mower has a high-performance engine with a high compression ratio, using a higher octane gasoline can prevent knocking and improve performance.
- High-altitude environments: At higher altitudes, air density is lower, which can lead to engine knocking. Using a higher octane gasoline can help to mitigate this problem.
- Engine pinging or knocking: If you notice your lawn mower experiencing engine pinging or knocking, switching to a higher octane gasoline might resolve the issue.
Choosing the Right Fuel for Your Lawn Mower: A Comprehensive Guide
When selecting gasoline for your lawn mower, consider these factors:
- Mower’s age: Older mowers may benefit from higher octane gasolines.
- Engine type: High-performance engines generally require higher octane fuel.
- Climate and altitude: Extreme temperatures and high altitudes can impact fuel performance.
- Manufacturer’s recommendations: Always consult your lawn mower’s owner’s manual for the recommended fuel type.
Gas Storage and Maintenance: Keeping Your Mower Running Smoothly
Once you’ve chosen the right gasoline, proper storage and maintenance are crucial to ensure your lawn mower runs efficiently and reliably:
1. Store Fuel Properly
- Use fuel stabilizer: Adding fuel stabilizer to your gasoline helps prevent the formation of gum and varnish, which can clog fuel lines and damage the engine.
- Store in airtight containers: Keep gasoline in airtight containers to prevent evaporation and moisture absorption.
- Store in a cool, dry location: Extreme temperatures can affect fuel quality, so store gasoline in a cool, dry location away from direct sunlight.
- Avoid prolonged storage: Gasoline degrades over time, so it’s best to use it within a few months.
- Don’t overfill the tank: Overfilling your mower’s gas tank can lead to spills and leaks.
2. Keep Your Mower Clean
- Clean the fuel filter: A clogged fuel filter can restrict fuel flow and reduce engine performance.
- Replace the spark plug: A worn or fouled spark plug can cause starting problems and affect engine performance.
- Check the air filter: A dirty air filter restricts airflow to the engine, reducing power and efficiency.
- Regularly inspect and clean the carburetor: A dirty carburetor can impede fuel flow and cause engine problems.
The Bottom Line
While the most common and affordable gas option for most lawn mowers is regular unleaded, understanding the intricacies of fuel and its impact on your mower is key to maximizing performance and longevity. Always refer to your mower’s manual for specific recommendations and consider factors like engine type, age, and operating environment when making your fuel choice. By prioritizing proper fuel selection, storage, and maintenance, you’ll ensure your lawn mower runs smoothly and efficiently for many seasons to come.
FAQ
What kind of gas should I use for my lawnmower?
It is best to use a blend of gasoline and ethanol. The amount of ethanol you should use will vary depending on your lawnmower’s manufacturer. You can find the recommended ethanol blend in your owner’s manual. Generally, a blend of 10% ethanol is ideal.
Using a higher ethanol blend can cause problems with your lawnmower’s engine, such as corrosion and clogging. This is because ethanol attracts moisture, which can cause rust and damage to the engine’s parts. It’s important to use fuel with the recommended ethanol blend to ensure your lawnmower runs smoothly and lasts for years to come.
Is it okay to use regular unleaded gasoline in my lawnmower?
Yes, regular unleaded gasoline is generally okay to use in most lawnmowers. However, it’s always best to check your owner’s manual for the recommended fuel type. Some lawnmowers may require a higher octane gasoline, such as premium unleaded.
Using regular unleaded gasoline is often cheaper than using premium unleaded, but it’s important to use the correct fuel type to avoid damage to your lawnmower’s engine. If you’re unsure about the recommended fuel type, it’s always best to err on the side of caution and use the higher-octane gasoline.
What about using gasoline with no ethanol?
Using gasoline with no ethanol, sometimes called “pure gas” or “non-oxygenated gas,” can be a good option for your lawnmower. It is less corrosive and can help prevent engine problems. However, it is not always readily available and can be more expensive.
If you can find gasoline with no ethanol, it is a good choice for your lawnmower. However, if you can’t find it, regular unleaded gasoline with 10% ethanol is a perfectly acceptable alternative.
What about using diesel fuel?
Using diesel fuel in your lawnmower is not recommended. Lawn mowers are designed to run on gasoline, and using diesel fuel can damage the engine. Diesel fuel has a different viscosity and combustion process than gasoline, and it will not burn properly in a gasoline engine.
Diesel fuel is also much heavier than gasoline and can clog the fuel lines and carburetor of your lawnmower. If you accidentally put diesel fuel in your lawnmower, you should drain the tank and refill it with gasoline as soon as possible.
Can I use gas from my car in my lawnmower?
While it is possible to use gas from your car in your lawnmower, it’s not the best idea. Car gas can contain additives that are not designed for lawnmower engines, and it could damage your lawnmower. It’s best to use gas specifically designed for small engines.
If you must use gas from your car, make sure it is unleaded and has a low ethanol content. However, if possible, stick to using gas designed for your lawnmower to keep it running smoothly and prevent any unnecessary damage.
Is it okay to use old gas in my lawnmower?
Using old gas in your lawnmower can cause problems, such as clogging and gumming up the engine. This is because gasoline degrades over time, becoming less volatile and more difficult to burn. Old gas can also contain moisture, which can lead to rust and corrosion.
It’s best to avoid using old gas in your lawnmower. If you have old gas, you can add a fuel stabilizer to help prevent it from degrading. However, if the gas is more than a few months old, it’s best to drain it and replace it with fresh gas.
Should I ever use premixed gas?
Premixed gas, which combines gasoline and oil, is often used for two-stroke engines. However, most modern lawnmowers have four-stroke engines that require separate oil and gas. Using premixed gas in a four-stroke engine can cause damage to the engine and lead to costly repairs.
Always consult your owner’s manual to determine the correct fuel type for your lawnmower. If you are unsure, it is always better to err on the side of caution and use straight gasoline rather than premixed gas.