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How often do lawnmowers need an oil change? – Tips & Tricks

Regularly topping up engine oil is not enough. Every time you mow your lawn, the oil loses lubricity due to heat exposure and dirt particles. Changing the oil fixes the problem and goes a long way toward extending the life of your valuable gasoline mower. This guide gives tips on how often it makes sense to change engine oil and explains how to do it.

The annual oil change is good – every 25 operating hours is better

When freshly filled, engine oil in the crankcase shimmers gold to amber. Heat, dirt, dust, and grass clippings darken the oil, which visibly impairs lubricity. The more difficult the conditions when mowing the lawn, the more quickly lawn mower oil loses its effectiveness. Therefore, in practice, the following intervals for an oil change have proven to be effective:

  • Commercial 4-cycle lawnmower with normal use: once a year, ideally in the spring.
  • Heavily used gasoline mower: every 25 operating hours.
  • Newly broken-in lawn mower: first oil change after 5 to 6 hours of operation.

If you have one of the now rare types of lawn mowers with a 2-stroke engine, the oil is burned at the same time as the gasoline, so changing the oil here is not part of the care and maintenance program.

Engine oil for lawn mower

oil for lawn mower

Change lawn mower oil correctly – this is what you should pay attention to

Changing lawn mower oil should always be done on a warm engine because this way more suspended particles are removed than when the engine is cold. In addition to the right type of oil, a collection container is the most important utensil.
Here’s how to proceed expertly:

  • Start the lawnmower and let it run for a few minutes.
  • Switch off the engine and disconnect the spark plug cap.
  • Place the collection container under the oil pan.
  • Unscrew the oil drain plug counterclockwise.
  • Allow all the used oil to run into the collection container.

Then tighten the oil drain plug clockwise. Now open the filler neck. Using a funnel, fill the fresh oil to just below the maximum mark in the tank and replace the cap. Start the mower again to check for leaks while the engine is idling.

Tips: Clean your lawnmower thoroughly after changing the oil. Even the smallest residue on the mowing deck will burn as blue-white smoke the next time you mow the lawn and give you a good scare. Therefore, wipe the device thoroughly with a damp cloth and a cleaner with grease dissolving power.

Refill oil in the lawnmower – how to do it?

In order for a gasoline-powered lawnmower to run like grease, the engine cannot do without fresh oil. Reaching for the right type of oil is just as crucial as how to go about it. This guide explains how to properly top off oil in your lawn mower.

2-stroke or 4-stroke engine? – Tips for the right lawn mower oil

Modern lawn mower models usually have a 4-stroke engine. Here, the gasoline is burned, whereas the oil remains in the engine to lubricate various components. Lawn mowers with a 2-stroke engine are rarely found. In these types, the gasoline and oil burn together, with the engine oil being mixed with the gasoline via a separate tank. Sometimes in 2-stroke engines, it is necessary to fill the engine oil directly into the gasoline tank.

The decision for the right engine oil is consequently related to which engine powers your lawnmower. In a 2-stroke engine, you can refill any standard 2-stroke oil. For 4-stroke lawn mowers, you ideally reach for special lawn mower oil of SAE 30 classification.

Topping up the oil in the lawn mower – Here’s how

Check the oil level when the engine is cold, you will get the most accurate reading. Since fresh oil is far from being topped up before every lawn mowing, determine the actual requirement in advance. Too little engine oil is just as detrimental to your gasoline mower as too high an oil level.
Here’s how to do it right:

  • Locate the oil fill cap on the crankcase.
  • Pull out the dipstick and wipe it with a cloth.
  • Insert the dipstick again and pull it out to read the oil level.
  • Using a funnel, add fresh oil to just below the maximum mark.

Various lawn mower models do not have an integrated oil dipstick. In this case, unscrew the cap and take a look inside the tank. A fill-up line will tell you how much engine oil needs to be topped up. It is important to note that the oil level is never below the minimum mark or above the maximum mark.

If you have a 2-stroke lawnmower with a single tank for the gasoline/oil mixture, the owner’s manual will provide more information on the proper mixing ratio. Separate fuel pumps are available at gas stations with the ability to set the mixture, fill it into a gasoline can and pour it into the lawnmower at home.

Tips: Often a headache for the gardener is how often to change the oil in the lawn mower. A good rule of thumb has been to change the oil at intervals of 25 hours of operation. If you are running in a new lawn mower, the first oil change is already scheduled after 5 operating hours.

How to change the lawnmower's engine oil - Video


Can you use car oil in a lawn mower?

Yes. Your braking system relies on the hydraulic fluid to amplify your foot’s pressure on the pedal. This is what allows you to stop a heavy, fast-moving vehicle with minimal effort.

Is there a difference between lawn mower oil and car oil?

You can use the same oil as automobiles, but owners should check manuals because these small engines are sensitive to additives and alternatives.

Can you put too much oil in a lawn mower?

For your lawn mower to work efficiently, it needs sufficient oil for lubrication. However, you need to be extra careful with the amount you allot to your machine. If there is too much oil in lawn mower, the engine can stop working properly.

David Muench (Carnes Mechanical)

David Muench (Carnes Mechanical)

Hey, I’m David. I’ve worked in a cars store for 6 years. I write reviews and guides, helping people to choose the most suitable technicals and best product for them. I’m happy to finally share my knowledge of the industry here, on CarnesMechanical.

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