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To Gas or Not to Gas: A Lawn Mower Dilemma

By Jeff Mercer · Updated September 24, 2026 · 4 min read
To Gas or Not to Gas: A Lawn Mower Dilemma
DisclosureSome links on this site are affiliate links — if you buy through one I may earn a small commission at no extra cost to you. It never decides an answer, and nothing here is a paid placement.

Have you ever had one of those moments where you’re trying to mow the lawn, but your mower won’t start?

Yeah, me too. I remember one time I was mowing and the mower just conked out on me. I didn’t have any gas in the tank and I was like, “Man, I should have checked that before I started.”

So that brings me to the question: is it better to leave gas in a lawn mower or not?

It’s a question that has probably crossed all of our minds at some point. Let’s dive in and see what the experts have to say about it.

The Pros and Cons of Leaving Gas in Your Lawn Mower

On the one hand, leaving gas in your lawn mower can be convenient. You don’t have to worry about remembering to fill up the tank before you mow, and you can just grab the mower and go.

Plus, if you have a small lawn, you might not go through a lot of gas in one mowing session, so the gas in the tank might not go bad before you need it again.

On the other hand, leaving gas in your lawn mower can also have some drawbacks. Gas can go bad over time, especially if it’s been sitting in the tank for a while.

If the gas goes bad, it can clog up the carburetor and other parts of the mower, which can cause it to run poorly or not start at all.

Additionally, leaving gas in the tank can also make the mower more prone to fire. Gas is flammable, and if it’s left in the tank for an extended period of time, it can start to break down and become more combustible. This can increase the risk of fire if the mower is stored in a garage or shed.

What the Experts Say

So, what’s the verdict? Is it better to leave gas in your lawn mower or not?

According to the experts, it’s generally best to empty the gas out of your mower when you’re finished using it for the season.

This can help prevent the gas from going bad and clogging up the carburetor. If you do decide to leave gas in the tank, it’s important to use a fuel stabilizer to help prevent the gas from breaking down.

It’s also a good idea to run the mower until it’s out of gas before storing it for the winter. This can help prevent stale gas from sitting in the tank and going bad.

FAQ

Can I leave gas in my lawn mower over the winter?

It’s generally not a good idea to leave gas in your lawn mower over the winter. As mentioned above, gas can go bad over time, especially if it’s left in the tank for an extended period of time.

It’s best to empty the gas out of the tank and run the mower until it’s out of gas before storing it for the winter.

What happens if I leave gas in my lawn mower over the winter?

If you leave gas in your lawn mower over the winter, it can go bad and clog up the carburetor and other parts of the mower.

This can cause the mower to run poorly or not start at all when you go to use it in the spring.

To avoid this issue, it’s a good idea to drain the gas from your lawn mower before you put it away for the winter.

You can do this by running the mower until it’s out of gas or by using a siphon hose to drain the gas from the tank. This will help prevent any damage to your mower and ensure that it’s ready to go when the grass starts growing again.

What if I need to use my lawn mower during the winter?

If you need to use your lawn mower during the winter, it’s best to empty the gas out of the tank and refill it with fresh gas before starting the mower.

This can help ensure that the mower is running at its best and prevent any issues caused by stale gas.

Can I store my lawn mower with gas in the tank?

If you need to store your lawn mower with gas in the tank, it’s important to use a fuel stabilizer to help prevent the gas from breaking down.

It’s also a good idea to store the mower in a well-ventilated area to help reduce the risk of fire.

The Bottom Line

In conclusion, it’s generally best to empty the gas out of your lawn mower when you’re finished using it for the season.

If you do decide to leave gas in the tank, it’s important to use a fuel stabilizer to help prevent the gas from breaking down and to store the mower in a well-ventilated area.

However, if you need to use your lawn mower during the winter, it’s best to empty the gas out of the tank and refill it with fresh gas before starting the mower.

So there you have it, [friend]. Now you know the pros and cons of leaving gas in your lawn mower and can make an informed decision about whether it’s the right choice for you. Happy mowing!

The Last Mow-Down

In the end, it’s up to you whether you want to leave gas in your lawn mower or not.

Just remember to use a fuel stabilizer if you do decide to leave gas in the tank and to store the mower in a well-ventilated area to help reduce the risk of fire.

And if you need to use your lawn mower during the winter, make sure to refill the tank with fresh gas before starting it up. Happy mowing!

Before you start the repairI'm a homeowner who does his own small-engine work, not a certified technician. Before any repair, pull the spark plug wire and let the engine cool. Anything involving blades under a raised machine, fuel system leaks or transmission internals — if you're not sure, have a dealer or small-engine shop look at it.
Jeff Mercer

Written by

Jeff Mercer

Hi, I'm Jeff. I look after about an acre of lawn, a riding mower, a zero-turn, a push mower that is older than some of my neighbours' cars, and a snowblower that only ever breaks the night before a storm. Doing my own repairs started as a way to save on dealer labour and turned into the part of yard work I actually enjoy.

GardenTooly is where I answer the questions people type into a search bar while standing next to a machine that won't behave: why the deck shakes, why the mower dies when it warms up, whether a bent blade shaft can be straightened, what the difference between two transmissions really means for you, and which fuel additive is worth the shelf space.

I'm not a certified small-engine technician and I don't sell equipment. Where I've done a job myself, I say so. Where an answer comes from the owner's manual, a service bulletin or a mechanic who knows more than me, I say that instead — and anything involving blades, fuel, jacked-up machines or a hydrostatic transmission gets a plain "take it to a shop" when that's the right call.