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Big Dog Zero Turns Use This GAS (Avoid Fuel Problems)

It’s important to use the right type of gasoline in a zero-turn. Using the wrong gas will not only cause performance and running problems, but it may also void manufacturer warranties.

Big Dog zero turn mowers require unleaded gasoline with a minimum 87 octane rating and no more than 10% ethanol content.

Running the wrong type of gas or old gas can cause damage to the fuel system and engine resulting in a significant repair bill. Take time to learn more about gasoline and how to properly care for it.

lawn mower gas can

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Follow all safety instructions provided in your equipment operator’s manual before 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 Big Dog Zero Turn Mowers?

While it is okay to use regular grade 87 octane fuel, the best gas to use in a Big Dog zero-turn mower is an ethanol-free fuel

Some things to keep in mind when purchasing and using gas for your Big Dog zero-turn lawn mower:

  • Only use fresh gasoline and don’t let it sit for extended periods of time.
  • Store in a dry area to keep water from mixing with the gas.
  • Use gasoline with an 87-octane rating or higher.
  • Make sure the gasoline has no more than a 10% ethanol content. The lower the content the better.
  • Refuel your zero turn in a well-ventilated area away from combustible products.

Choosing Gas for Your Big Dog Zero Turn Lawn Mower

There are a variety of fuels offered at fuel stations. Some of them include regular, midgrade, premium, diesel, E15 (up to 15% ethanol), E85 (up to 85% ethanol), and REC90 (ethanol-free).

With so many options, it can be confusing when selecting the right gas for your Big Dog.

Buy Fresh Gas

Because can begin to break down and become less effective as quickly as 30 days after purchase, it’s important you buy fresh unleaded gas with low ethanol content.

Only buy enough fuel that you are able to consume within 30 days to protect your fuel system.

If you do end up purchasing more fuel than you can use this quickly, you must stabilize it using a fuel additive. I discuss the use of fuel additives and my recommendation a little further into the article.

Avoid High Amounts of Ethanol

Ethanol is added to most types of gasoline. This is a plant-based fuel used to make traditional gasoline more friendly to the environment.

Some ethanol is okay to run in most vehicles without harm, however, ethanol can have a negative effect on the small engine used on your Big Dog mower.

Avoid using gasoline that has an ethanol content greater than 10%. This includes fuels sold as E15 and E85 which contain ethanol levels at 15% and 85% respectively.

How ethanol negatively affects your mower:

  • Ethanol attracts moisture to the fuel system.
  • Water and ethanol separate from the gas and sink to the bottom of the fuel tank.
  • Leaves behind a varnish and gummy deposits that clog fuel passageways.
  • Highly corrosive and damaging to fuel components and the engine.

Purchase a High-Quality Fuel for Your Big Dog Mower

While buying expensive fuel isn’t always the best, I do recommend buying the best quality gas with a low ethanol content if you can afford to. Another option for fuel is ethanol-free fuel.

Ethanol-free fuel, also known as recreation fuel is the best option to run in a gas-powered Big Dog mower. It has less damaging effects on your fuel system than regular gas because it doesn’t break down like fuels that contain ethanol.

Ethanol-free fuel is more expensive than regular or premium gas. You can find ethanol free fuel at fuel stations and hardware stores.

  • 4-cycle fuel in canisters: Available at hardware, automotive, and online.
  • REC-90 fuel at fuel stations: Select fuel stations offer recreation fuel. You can find a fuel station that offers ethanol-free fuel at

Use a Fuel Additive in Your Big Dog Zero Mower

While ethanol-free fuel is best, I use high-quality unleaded gasoline with low ethanol content.

I just make sure to add a fuel additive to each tank of fuel to reduce the fuel supply problems I may encounter by running old fuel. I also try not to buy excess fuel and let it sit for long periods.

The fuel additive I prefer is Sea Foam Motor Treatment.

  • Keeps fuel stable
  • Reduces moisture
  • Acts as a fuel system cleaner

This product should be used in your fuel tank when storing excess fuel and when storing your lawn mower with fuel during the off-season.

Read more about the advantage of Sea Foam here and why I choose to add it to all of my small engine gas.