How Often to Change Lawn Mower Oil

Wondering How Often to Change Lawn Mower Oil?

Many new homeowners may not consider the maintenance requirements of a gas-powered lawn mower. However, their engine – much like a car engine – does require tune-ups and regular light maintenance to run in optimal condition. That being said, your commuting car runs every day, but your lawn mower? It might sit idle for a week or two at a time, and you might only use it for 6 months out of the year. So you may be wondering how often to change lawn mower oil to properly maintain your mower. I’ll explain in this article.

Trust and Accuracy Information

This article was last updated on by Lawn Chick Owner Sarah Jameson
Article content reviewed for accuracy by Certified Horticulturist Nicole Forsyth, M.S.

So – How Often to Change Lawn Mower Oil for Best Results?

Professionals recommend that you change the oil in your lawn mower every 20-50 hours of operation. For most people, this means that if you change your mower’s oil once every season (at the beginning of the year as part of your spring mower maintenance routine or when you winterize your mower), you’ll be just fine.

That said, every mower (and lawn, and owner) is different. So here are some …

Best Practices

The owner’s manual of your mower will be the best place to look first.

The manufacturer is the best source of knowledge for the inner workings of your machine. Even if you don’t have the owner’s manual on hand, most can be found quickly online as long as you know the make and model of your lawn mower.

Lawn Mower Oil Change Frequency

Even if you use your mower lightly or infrequently, I recommend that you change your mower’s oil once a season, or every 50 hours of operation – whichever is more frequent.

I do it as part of my annual tune-up to start each year. I give my mower a fresh air filter, spark plug, change the oil, and check the mower’s blade to make sure it doesn’t need to be sharpened or replaced.

This costs less than $25 in materials and takes about 30 minutes to do. My mower starts on the first pull every time.

Signs That it Might Be Time to Change Your Lawn Mower Oil

Regardless of how often you change the oil, you should check the level periodically throughout the season, and definitely do so at the start of each year.

There are a few telltale signs that it’s time to change your lawn mower’s oil.

Your lawn mower doesn’t have a dashboard indicator light that can tell you when there might be a problem, so you have to do your own due diligence.

Use the Dipstick to Check the Level

Similar to a car engine, you can use the dipstick in the oil well of the lawn mower engine to make sure that the oil is at the right level. It is best to check this before starting the lawn mower as the movement of the oil once the engine is started can falsely elevate the oil level on the dipstick.

Checking before starting the mower can also potentially prevent bad oil from being taken in by the engine.

It’s good practice to check a couple of times by pulling the stick, wiping it clean, then dipping it again, and repeating to ensure that you get an accurate measure.

Use the Dipstick to Check the Quality

The dipstick can also offer more information. It can be a great way to quickly get a sense of the quality of the oil remaining in your mower.

Fresh and good quality oil should be amber in color and free of debris.

If your dipstick pulls up black oil or has bits of debris showing, then it’s definitely time to change your oil.

If the oil is still a good amber color and is free of debris but perhaps a bit low, then it’s okay just to top it up a bit by adding oil directly into the oil well of your lawn mower.

How Frequently to Change Lawn Mower Oil

You’ll be able to tell if the oil level is too low or too high based on the indicators on the dipstick itself that will usually have markings that read “full” or “low”.

My one tip about topping off your mower’s oil level is to add a little, then check again.

Many people add too much oil, and it’s easier to add a little at a time, than to waste oil by having to dump some out after overfilling your reservoir.

Better Late Than Never

If you’ve had a mower for years and haven’t ever checked or changed the oil, don’t despair!

Now is a perfect time to start, and many well-made lawn mowers are resilient to a certain degree of neglect.

Just because you’ve managed to use your mower for two (or more!) seasons without any problem, doesn’t mean you won’t run into problems that could send your mower to the scrap yard.

So head to the hardware store, buy the right oil for your mower, and get her purring like a kitten the next time you mow.

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Sarah Jameson’s blog, Lawn Chick, is read by over 2 million homeowners each year and she is regularly cited as an expert source of lawn care knowledge by major publications. Her goal is to meet you where you are, and help you achieve a yard you’ll be proud of. Ready to take the next step toward improving your lawn? Grab her free lawn care cheat-sheet: What to Do When - Take the Guesswork Out of Lawn Care, or upgrade your garage by browsing her favorite DIY lawn care products.

2 thoughts on “Wondering How Often to Change Lawn Mower Oil?

  1. Dan

    Great Advice. I think in areas where the machine is used weekly it may be best to change the oil twice per year . But your advice of a max of 50 hours is spot on , even if the oil still looks good … it may have broken down sufficiently to warrant a change.

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