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Lawn mowers are a common sight in American homes these days. Use of these machines, which come in both electric and gasoline versions, tends to follow a very predictable cycle. Across the U.S., mowing season generally begins in March or April, extending well into October in some regions. Once November arrives, falling temperatures and slower grass growth dramatically reduce how often lawns need cutting. Thus, it is not uncommon for lawn mowers to remain unused from November to March.

While electric mowers can usually be unplugged and stored without much fuss during this lean period, gasoline-powered models typically require a bit more care. One important task is to ensure that the lawn mower doesn’t face fuel-related issues and easily starts up when spring comes around. Typically, there are two key ways to go about this: the first method involves completely draining the fuel tank of gasoline before storage, while the second option is to fill up the machine with fresh fuel and add a fuel stabilizer to the tank.

Fuel stabilizers are a popular choice for lawnmowers, with mower manufacturers and regular users recommending their use. Both storage methods have pros and cons, but adding a fuel stabilizer to extend the life of the stored gasoline is easier and more cost-effective. So, while a mower doesn’t strictly require a fuel stabilizer to survive the off-season, adding it to the fuel tank is a perfectly valid option.

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Like other hydrocarbon-based fuels, gasoline has a limited shelf life. Under ideal conditions, regular gasoline can be safely stored in sealed containers for up to a year. However, lawn mowers are usually stored in less-than-ideal conditions, reducing the gasoline’s life to just a month or so. Besides being subject to significant temperature fluctuations, long-term storage also causes the fuel to interact with the materials the tank is made of.

While these issues do not usually occur when the lawn mower is frequently used, storing a lawn mower with a tankful of gas can cause the fuel to deteriorate rapidly. When you try to restart the lawn mower with this deteriorated fuel, the machine may exhibit several symptoms, ranging from starting difficulty and pinging noises from the engine to a noticeable increase in engine vibration. It is also generally not a good idea to use stale fuel, as it could eventually damage the engine’s fuel system.

Adding fuel stabilizer to the lawn mower’s gas tank before storage helps prevent the gasoline from going stale, thereby protecting the engine from potential damage and ensuring it starts without issues. Thus, adding stabilizer to a mower’s gas tank before storing it for several months is generally a good idea. Of course, there’s less need for a fuel additive if you use your gasoline-powered lawn mowers regularly, with no long periods of storage.