How Often Do You Put Oil in a Lawn Mower?

The hum of a well-maintained lawn mower is a symphony of summer – a sign of a well-kept lawn and a happy homeowner. But like any machine, your lawn mower needs proper care and attention, and one of the most important aspects of this care is keeping the engine well-oiled. This article will guide you through the process of understanding how often to change your lawn mower oil, the factors that influence this frequency, and the simple steps involved in this essential maintenance task.

How Often Should I Change My Lawn Mower Oil?

The general rule of thumb is to change your lawn mower oil every 25 hours of use or once per season, whichever comes first. This guideline ensures that your engine is adequately lubricated and protected from wear and tear. However, several factors can influence this frequency, and it’s essential to consider them for optimal engine health.

Factors Affecting Oil Change Frequency

1. Type of Lawn Mower:

a. Gas-Powered Lawn Mowers:

Gas-powered lawn mowers require regular oil changes due to the combustion process that generates heat and friction. This heat can degrade the oil over time, leading to increased wear and tear on engine components.

b. Electric Lawn Mowers:

Electric lawn mowers generally don’t require oil changes as they lack combustion engines. They are powered by electricity, so oil lubrication isn’t a factor.

2. Usage Intensity:

a. Frequent Use:

If you frequently use your lawn mower, especially in demanding conditions like hilly terrain or thick grass, the oil will degrade faster. This requires more frequent oil changes, possibly every 15-20 hours of use.

b. Occasional Use:

For occasional users, an annual oil change might be sufficient.

3. Oil Quality:

a. Synthetic Oil:

Synthetic oil offers superior heat resistance and longevity compared to conventional oil. It can extend your oil change intervals to 50 hours or even longer. However, check the manufacturer’s recommendations for the specific type of oil.

b. Conventional Oil:

Conventional oil is generally more affordable but breaks down faster. Sticking to the recommended 25-hour interval is crucial for conventional oil.

4. Operating Conditions:

a. High Temperatures:

Extreme heat can accelerate oil degradation, shortening its lifespan. In hot climates, more frequent oil changes may be necessary.

b. Dusty Environments:

Dusty environments can contaminate the oil, leading to engine wear. If you mow in dusty areas, consider changing your oil more frequently.

How to Change Your Lawn Mower Oil

Changing your lawn mower oil is a relatively straightforward process. Follow these steps for a smooth and efficient oil change:

  1. Safety First:

  2. Wear safety goggles and gloves to protect your eyes and hands.

  3. Make sure the lawn mower is cool and the engine is off.
  4. Disconnect the spark plug wire to prevent accidental starting.

  5. Locate the Oil Drain Plug:

  6. Your lawn mower’s oil drain plug is typically located on the bottom of the engine.

  7. It may have a hexagonal or square shape.

  8. Position a Catch Pan:

  9. Place a suitable container, such as an oil drain pan, underneath the drain plug to collect the old oil.

  10. Open the Drain Plug:

  11. Use a wrench or socket to loosen and remove the drain plug.

  12. Let the old oil drain completely into the catch pan.

  13. Replace the Drain Plug:

  14. Clean the drain plug threads with a cloth or wire brush.

  15. Reinstall the drain plug, ensuring it’s tightly secured.

  16. Add New Oil:

  17. Locate the oil fill cap (usually on top of the engine).

  18. Pour the recommended amount of fresh oil into the fill cap. Check your lawn mower’s manual for the correct oil type and quantity.

  19. Wipe Up Spills:

  20. Clean up any oil spills around the engine with a clean cloth or absorbent material.

  21. Reconnection Spark Plug Wire:

  22. Reattach the spark plug wire to ensure the engine doesn’t start accidentally.

  23. Start the Engine:

  24. Start the engine for a few minutes to circulate the fresh oil.

  25. Check for any leaks.

  26. Dispose of Old Oil Properly:

  27. Dispose of the old oil responsibly. Never pour it down the drain.

  28. Look for designated oil recycling centers or check with your local waste disposal company for disposal options.

Maintaining Your Lawn Mower for Longevity

Regular oil changes are crucial for maintaining your lawn mower’s longevity. But it’s only part of the equation. Other maintenance practices also contribute to a healthy engine:

  • Air Filter Cleaning:

    • A dirty air filter restricts airflow to the engine, reducing performance and leading to increased wear.
    • Clean or replace the air filter regularly according to the manufacturer’s recommendations.
  • Spark Plug Inspection:

    • A worn-out spark plug can affect engine performance.
    • Inspect the spark plug regularly and replace it as needed.
  • Blade Sharpening:

    • Sharp blades cut cleanly, preventing stress on the engine.
    • Sharpen your lawn mower blades periodically to ensure optimal performance.
  • Fuel System Maintenance:

    • Use fresh, clean gasoline to prevent fuel-related issues.
    • Consider adding a fuel stabilizer to gasoline stored for extended periods.


Keeping your lawn mower well-oiled is essential for its smooth operation and longevity. By understanding the factors influencing oil change frequency and following a regular maintenance schedule, you can ensure your lawn mower remains a reliable partner in maintaining a beautiful and healthy lawn. Remember to consult your lawn mower’s manual for specific recommendations and guidance regarding oil type, quantity, and maintenance intervals. With proper care and attention, your lawn mower will continue to hum happily for years to come, ensuring you spend more time enjoying your lawn and less time troubleshooting engine problems.


1. How often should I change the oil in my lawnmower?

The recommended oil change interval for lawnmowers is typically around every 25 hours of operation or once a season. However, this can vary depending on the type of mower, the quality of the oil, and the frequency of use. It’s always a good idea to consult your mower’s owner’s manual for specific guidance.

If you use your mower frequently, especially in hot weather, you should change the oil more often. Neglecting oil changes can lead to engine wear and tear, decreased performance, and ultimately, premature failure.

2. What kind of oil should I use for my lawnmower?

The type of oil you need for your lawnmower will be specified in the owner’s manual. Generally, SAE 30 oil is recommended for most gasoline-powered lawnmowers. However, you may need a different type of oil if your mower has a specific engine or operates in extreme temperatures.

It’s important to use the right type of oil to ensure proper lubrication and prevent engine damage. Using the wrong type of oil can lead to reduced engine performance, increased wear and tear, and even engine failure.

3. How do I change the oil in my lawnmower?

Changing the oil in your lawnmower is a relatively simple process. First, let the engine cool completely to prevent burns. Then, locate the oil drain plug on the bottom of the engine. Place a drain pan underneath the plug and unscrew it to allow the oil to drain.

Once the oil has drained, reinstall the drain plug and tighten it securely. Next, remove the oil fill cap and pour the correct amount of new oil into the engine. Be sure to check the oil level using the dipstick and add more oil if needed.

4. What happens if I don’t change the oil in my lawnmower?

If you neglect to change the oil in your lawnmower, the oil will become contaminated with dirt, metal shavings, and other debris. This contaminated oil will not lubricate the engine properly, leading to increased friction and wear and tear.

Eventually, the engine will begin to run poorly, lose power, and eventually seize up completely. This can result in expensive repairs or even the need to replace the entire engine.

5. Can I use regular motor oil in my lawnmower?

While some people may think that regular motor oil is suitable for lawnmowers, it’s generally not recommended. Regular motor oil is typically designed for car engines and may contain additives that are not compatible with lawnmower engines.

Using the wrong type of oil can lead to engine damage and premature failure. It’s best to stick with the oil type recommended in your lawnmower’s owner’s manual.

6. How do I know if my lawnmower needs an oil change?

There are a few signs that your lawnmower may need an oil change. The oil may be dark or murky instead of its original clear color. You might also notice a burning smell coming from the engine.

Finally, if your lawnmower starts to run poorly or lose power, it’s a sign that the oil is not lubricating properly and an oil change is needed.

7. What should I do with the old oil?

Old lawnmower oil should not be poured down the drain or into the ground. It is considered hazardous waste and can harm the environment.

Instead, take it to a local recycling center that accepts used motor oil. You can also find specialized containers for used motor oil at most auto parts stores. Always dispose of used oil responsibly to protect the environment.

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