How Often to Change Lawn Mower Oil

In Brief: How Often to Change Lawn Mower Oil

Change the oil on a lawn mower after every 50 hours of use or annually, whichever comes first. If your mower is older, or if you mow in rough terrain or very hot temperatures, change the oil every 25-40 hours of use instead. Check oil levels before every use.

A lawn mower engine is just like all other small engines. Without clean oil, it won’t run properly. You need to change the oil regularly to keep it in top shape. But, do you really know how often to change lawn mower oil in your machine?

While every mower engine is a little different, there are a few guidelines that can be applied broadly.

How Often to Change Lawn Mower Oil

Oil change frequency is usually measured in terms of hours of use. This measurement is exactly what it sounds like: the number of hours you’re running and using your mower.

On average, most lawn mowers need an oil change after every 50 hours of use. However, the frequency of lawn mower oil changes depends on a few specifics about your mower. Namely, the age of the mower, how often you mow, where you mow, and the type of mower you use.

When to Change the Oil on Your Lawn Mower
Hours of UseMower Circumstances
5 hoursNew engine. Change after the first 5 hours of use.
20-40 hoursOld mowers, or any mower used in rough terrain/very hot temps
50 hoursMinimum requirements for all lawn mowers.

Age of the Mower

There are two things you need to consider with the mower’s age.

Brand new engines need an oil change after about five hours of use. This is a one-time event that’s exclusively for brand new engines. After this first oil change, you can continue changing the oil as usual.

For older engines, oil changes should be more frequent. Instead of every 50 hours of use, older mowers would benefit from oil changes closer to every 35-40 hours of use.

Frequency of Mowing

Logically, if you use your mower more often, you’ll reach the 50 hours of use faster. However, 50 hours of use only applies when you’re mowing regularly. If your mower sits for long periods of time, such as over the fall and winter, you need to change the oil before you use it.

Even if you mow infrequently, oil should still be changed annually, whether you’ve reached 50 hours of use or not. You can do an oil change as part of your winterizing before you store the mower. Once annually is usually enough for a mower in good condition that doesn’t get frequent use.


Where you mow makes a big difference in how hard the engine works. Engines that work harder need more frequent oil changes. If the terrain you mow is wet, thick, hilly, heavily dusty, or full of small debris, you need to change the oil more regularly. This might mean after every 25 hours of use if the environment is too rough.

Temperature is another environmental factor to consider. If you mow where it’s very hot or very cold, the mower engine needs clean oil to run well. While cold weather is unlikely with a mower, a heat wave in the summer could put extra stress on your mower engine, requiring clean oil to keep it cool and lubricated.

In very hot areas, change the oil every 25 hours of use.

Type of Mower

Some mowers have different types of engines. In general, lawn mowers use either 2-stroke or 4-stroke engines. While all riding lawn mowers use 4-stroke engines for their higher power, some push mowers use 2-stroke engines.

You can tell which is which by looking at the oil and fuel valves. 2-stroke engines use a combination fuel mixed with oil while 4-stroke and larger engines have separate fuel and oil. If the mower uses a 2-stroke engine, these oil change frequency guidelines do not apply.

Manufacturer’s Recommendations

Above all, the most important thing to check is what the lawn mower manufacturer says about the frequency of oil changes. Depending on the brand and model of the mower, the recommendations may vary. While 50 hours of use is a good baseline, it might not be the best advice for every lawn mower.

Check the owner’s manual. If you don’t have a physical copy, look it up online. Use the manufacture’s recommendations as your baseline.

Always check the oil levels in your mower before you use it. If it’s low, top it up.


Lawn mowers need their oil changed regularly. Doing it every 50 hours of use or annually helps you keep your mower in top shape for longer.




About Karen Taylor

Karen is an expert woodworker. He has been working as a professional in the domain for more than 12 years now. She has experience of working on a variety of power and other tools while working on her projects.

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