Whether you just purchased a riding mower or you have been using your riding mower for years, it’s important to know the type of gas you should be running through your mower.

Understanding the effects gasoline has on your mower will help you make the best decision when fueling your riding mower.

Riding lawn mowers use unleaded gasoline with a minimum octane rating of 87 and a maximum ethanol content of 10%. This type of gasoline can be easily found at the local gas station and sold as regular or E10 gas.

While most riding mowers use unleaded gasoline, some will require other types of fuel like diesel, and it is critical that you look over your manufacturers’ guide to see what works best for your lawn mower.

However, if you are using any major brand riding lawn mower that has a 4-cycle gas engine, traditional unleaded gasoline will be the best choice. 

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Follow all safety instructions provided in your equipment operator’s manual prior to diagnosing, repairing, or operating.Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.

What is the Best Gas for Riding Lawn Mowers?

While it’s fine to use unleaded gasoline with a low ethanol content, the best fuel to use in a gas-powered riding lawn mower is an ethanol-free fuel.

This fuel can be found at select fuel stations and sold as recreation fuel (REC-90). It can also be found in canisters sold at hardware stores. Pure-gas.org provides a list of fuel stations that offer ethanol-free gas in the United States and Canada.

Ethanol-free gasoline is the more expensive fuel choice. While it’s more costly than regular gas, it will run cleaner through the fuel system. It will cause fewer problems that can affect starting and running the riding mower. Keep reading for the negative effects ethanol has on a riding mower and why an ethanol-free fuel is best.

Choosing Gas for Your Lawn Mower

The fuel used is vital to extending the lifetime of the mower and ensuring it runs smoothly. Follow these tips to ensure you are buying quality gas for your riding mower:

Always Buy Fresh Gas for Your Lawn Mower

One of the absolute most crucial steps to ensuring you are using quality gas is to always refill your mower with fresh fuel. 

The problem is that many will fill up a plastic gas can for their mower and allow this to sit for long periods of time. When left outside, this gas is subject to the elements and can become less potent or even ineffective over time. 

The best option is to always get gas prior to mowing and ensure that you use the gas you have purchased within 30 days. You will want to get your gas from a larger, well-known gas station.

This ensures that the gas you are choosing is of higher quality and often fresher than smaller gas stations may offer.

Avoid High Amounts of Ethanol in Your Lawn Mower Gas

Ethanol, a plant-based product added to most gasoline, works well in a car and truck but can be damaging to the small engine in your riding mower. Ethanol is corrosive to the lawn mower’s fuel system. It also leaves behind gummy deposits that can create fuel restrictions.

Ethanol-based gas attracts moisture from the air and when the gas begins to break down, the water and ethanol mixture will sink to the bottom of the fuel tank.

Running this solution can cause your lawn mower to run extremely hot causing your engine to overheat and experience significant engine damage.

Only use gasoline with a maximum ethanol content of 10%. Avoid using gasoline with a higher content than this often sold as E15, E30, and E85 fuels. These contain up to 15%, 30%, and 85% ethanol respectively.

Purchase High-Quality Fuel for Your Riding Lawn Mower

Buying more expensive unleaded gas is not always the best, but I do highly recommend purchasing the best gas that is affordable to you.

If you buy higher-end gas and worry you will not use all of it, there are some ways to keep gas fresh. The best way to store gas is by adding an additive to stabilize your fuel.

Stabilize Fuel for Your Riding Lawn Mower

Stabilizing fuel allows it to last a little longer without breaking down. Add this to your gas when you are unable to use it within 30 days.

As a precaution, I choose to add it to every tank of gas in my lawn mower. Always add a fuel additive to your fuel when it is fresh. Once the fuel degrades, the additive cannot reverse this process.

I use a product called Sea Foam Motor Treatment in my gasoline. It stabilizes the gas and reduces moisture in the gas while cleaning the fuel system. Read more about the benefits of Sea Foam in my article here.

How to Store Gas for Your Riding Lawn Mower

Here are a few tips for storing gasoline for a riding lawn mower:

• Use a gas can designed to hold unleaded gasoline. Other types of containers can break down.
• Add a fuel stabilizer to the gas to keep it from breaking down quickly.
• Always rotate the gas you store to use the oldest fuel first.
• Keep the gas in a dry location away from combustible items.

In Summary

Truly refueling your lawn mower should not be a stressful process and is relatively simple, even for beginners. The basics to keep in mind are simply:

• Get fresh fuel from a busy fuel station.
• Consume it within 30 days.
• Use a fuel stabilizer if you are unable to use it within 30 days.
• Avoid ethanol contents greater than 10%.
• Store fuel indoors away from moisture.

If you have any questions concerning your lawn mower, the operator’s manual is always a great place to start for additional help.