What Kind of Gas Does a Lawn Mower Use? 🤔

The whirring of a lawn mower is a familiar summer sound, but have you ever stopped to consider what fuels that powerful engine? It’s not just any gas you can find at the pump – lawn mowers have specific fuel requirements. This article will delve into the world of lawn mower fuel, explaining what type of gas is best, the reasons behind its unique properties, and how to properly store and use it for optimal performance and longevity of your mower.

Short Answer: Lawn mowers typically use regular unleaded gasoline, often with an octane rating of 87 or 89. However, adding an octane booster or fuel stabilizer can extend the life of your fuel and prevent engine issues.

Understanding the Fuel Needs of Your Lawn Mower

Lawn mower engines are designed to operate on gasoline, a readily available and relatively inexpensive fuel source. However, the gas used in your lawnmower is not the same as what you put in your car. There are specific factors that determine the type of gas suitable for your lawn mower:

1. Octane Rating: The Power Behind the Cut

Octane is a measure of the fuel’s resistance to knocking or pinging in the engine. Higher octane ratings indicate a greater resistance to knocking. While a high-octane gasoline might seem like a good idea for a lawn mower, it’s usually not necessary. Most lawn mowers are designed to operate efficiently on regular unleaded gasoline with an octane rating of 87 or 89.

  • Why Regular Unleaded is Enough: Lawn mower engines typically operate at lower compression ratios than car engines, making them less susceptible to knocking. Using higher octane gasoline in a lawn mower won’t improve performance and may even be a waste of money.

2. Fuel Additives: Enhancing Performance and Durability

The type of gas used in a lawn mower can affect its performance and longevity. While regular unleaded gasoline is the base, adding certain additives can significantly enhance the fuel’s qualities:

a. Ethanol: A Controversial Component

Ethanol is often added to gasoline as a biofuel. While it can help reduce emissions, it also has some drawbacks:

  • Increased Fuel Degradation: Ethanol absorbs moisture, leading to fuel degradation and potential engine problems.
  • Separation and Corrosion: Ethanol can separate from gasoline over time, forming a sticky residue that clogs fuel lines and damages fuel system components.

b. Fuel Stabilizers: Protecting Against Deterioration

Fuel stabilizers are additives that prevent the degradation of gasoline over time. They help to prevent the formation of gum and varnish, which can clog fuel lines and injectors, leading to engine problems.

  • Important for Storage: Fuel stabilizers are particularly important if you’re storing your lawn mower for an extended period, as gasoline can deteriorate even when not in use.

c. Octane Boosters: Enhancing Ignition

Octane boosters are additives that increase the octane rating of gasoline. While they are not usually necessary for lawn mowers, they can be helpful if your engine experiences knocking or pinging, particularly under high-load conditions.

Choosing the Right Fuel for Your Lawn Mower

Here’s a simple breakdown of the best fuel choices for your lawn mower:

  • Regular Unleaded Gasoline (87 or 89 octane): The most common and generally recommended fuel for lawn mowers.
  • Fuel Stabilizer: Always recommended, especially for long-term storage.
  • Octane Booster: Consider it only if your lawn mower experiences knocking or pinging, but it’s not usually necessary.
  • Ethanol-Free Gasoline: A great option to prevent fuel degradation and minimize engine issues, but it may be more expensive and less readily available.

Understanding the Risks of Using the Wrong Fuel

Using the wrong type of fuel in your lawn mower can lead to various problems:

  • Engine Knocking: Using gasoline with an octane rating lower than what your lawn mower requires can lead to engine knocking or pinging, potentially damaging engine components.
  • Fuel System Clogging: Gasoline with high ethanol content can lead to fuel system clogging, causing engine problems and reducing efficiency.
  • Premature Engine Wear: Fuel degradation from improper storage or the use of ethanol-containing gasoline can lead to premature wear on engine components.

Maintaining Your Lawn Mower: Fuel Storage and Handling

Proper fuel storage and handling are crucial for ensuring optimal performance and longevity of your lawn mower.

1. Storage: Minimize Fuel Deterioration

  • Use Fuel Stabilizer: Add fuel stabilizer to your gasoline tank before storing your lawn mower.
  • Store in a Cool, Dry Place: Avoid storing your lawn mower in direct sunlight or humid environments.
  • Empty the Tank: If you’re not planning to use your lawn mower for an extended period, it’s best to empty the fuel tank and run the engine until it stops to clear the fuel lines.

2. Handling: Keep it Clean

  • Use Clean Fuel: Always use fresh, clean gasoline and avoid filling the tank from a rusty or contaminated source.
  • Keep the Fuel System Clean: Periodically inspect and clean your fuel filter and fuel lines to prevent clogging.

Conclusion: Keep Your Lawn Mower Running Smoothly

By understanding the specific fuel requirements of your lawn mower, choosing the right type of gasoline, and practicing proper fuel storage and handling, you can ensure that your lawn mower runs smoothly and efficiently for years to come. Remember, a little effort in choosing and caring for your fuel can go a long way in keeping your lawn looking its best.


What kind of gas do most lawnmowers use?

Most gasoline-powered lawnmowers use regular unleaded gasoline, which is the same type of fuel you would use in your car. However, some older lawnmowers may require premium unleaded gasoline. You can check your owner’s manual to see what type of gasoline is recommended for your specific model.

It is important to note that using the wrong type of gasoline can damage your lawnmower. For example, using premium gasoline in a lawnmower that is designed to use regular gasoline can cause engine knock and other problems.

Should I use gasoline with ethanol in my lawnmower?

It is generally not recommended to use gasoline with ethanol in your lawnmower. Ethanol can cause problems with your lawnmower’s fuel system, such as clogging the carburetor or fuel lines. It can also attract moisture, which can lead to corrosion and other problems.

If you do use gasoline with ethanol, it is important to use a fuel stabilizer to help prevent these problems. You should also drain the fuel tank and carburetor before storing your lawnmower for long periods.

How do I know what kind of gas my lawnmower needs?

The best way to know what kind of gas your lawnmower needs is to check the owner’s manual. The manual will provide specific instructions on the type of gasoline, fuel octane rating, and any other fuel-related recommendations.

If you don’t have your owner’s manual, you can often find it online. Simply search for the make and model of your lawnmower on the manufacturer’s website.

Can I use gas from my car in my lawnmower?

Yes, you can generally use gas from your car in your lawnmower. However, it is important to make sure that the gas you use is unleaded and has the correct octane rating for your lawnmower.

If you are unsure about the octane rating, it is always best to err on the side of caution and use a higher octane rating. For example, if your lawnmower requires 87 octane gasoline, it is perfectly fine to use 89 or 91 octane gasoline.

What happens if I use the wrong gas in my lawnmower?

Using the wrong type of gas in your lawnmower can lead to a number of problems, including:

  • Engine damage: Using the wrong octane rating can cause engine knock or detonation, which can damage the engine.
  • Fuel system problems: Using gasoline with ethanol can cause problems with the fuel system, such as clogging the carburetor or fuel lines.
  • Performance issues: Your lawnmower may not run as smoothly or efficiently if it is using the wrong type of gasoline.

How long can I store gasoline in my lawnmower?

It is not recommended to store gasoline in your lawnmower for extended periods of time. Gasoline can go bad over time, especially if it is exposed to air and moisture. This can lead to problems with the fuel system and engine.

If you need to store gasoline in your lawnmower, it is best to use a fuel stabilizer. A fuel stabilizer will help to prevent the gasoline from going bad and will extend its shelf life.

What is the best way to store my lawnmower for the winter?

When storing your lawnmower for the winter, it is important to drain the fuel tank and carburetor. This will help to prevent the fuel from going bad and causing problems with the engine. You can also add a fuel stabilizer to the fuel tank before draining it.

Additionally, it is a good idea to clean and lubricate the lawnmower before storing it. This will help to keep it in good condition and make it easier to start up in the spring.

Leave a Comment