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What Kind Of Oil Goes In A Lawn Mower? All You Need To Know!

In cold weather conditions, you should use SAE 10W-30 or SAE 5W30 oil in your lawn mower. SAE 30 is usually the best option for smaller mowers and warm weather conditions. However, commercial mowers perform best on 15W30. Depending on the model, synthetic oil may also be suitable.

Are you new to landscaping or gardening? If so, you may be wondering what kind of oil goes in a lawn mower. It’s crucial to select the correct type to not damage your machine, but there are many different varieties. You can always consult your mower’s manual, but this can be time-consuming. 

In this guide, I give you a detailed breakdown of the different lawn mower engine oils. I explain the properties of each one so you can learn if it is suitable for your mower. Lastly, I teach you how to change your lawn mower oil. 

Blue Lawn Mower

Why Do Lawn Mowers Need Oil?

Similar to other garden power tools, like lawn or garden tractors, lawnmowers need oil to function correctly. This is because the oil lubricates the different parts of the engine. By doing so, it reduces friction and overall wear and tear. 

However, not all lawn mowers use the same kind of engine oil. This is because each oil has a different viscosity, which means how quickly it flows under certain conditions. 

What Are The Different Types Of Lawn Mower Engine Oil?

Check out our infographic to understand what oil you should use based on the outside temperature:

Lawn Mower Oil Types And Temperatures They Work Best At Infographic

What Do The Numbers Mean?

Depending on your lawn mower’s size and the climate where you live, you have a few different engine oil options. They each have a code with numbers and letters, which explain how well the oil performs under certain conditions. 

SAE is the Society of Automotive Engineers, which developed a measurement scale for different oils. Their numbers describe the flow of the oil, with lower numbers flowing best at lower temperatures. 

Multigrade oil performs well in high and low temperatures. It has two numbers separated by a “W.” The “W” stands for winter, and the number before it describes the oil’s viscosity at low temperatures. Conversely, the number after the “W” shows its performance in high temperatures. 

A Chart Of Viscosity Grades For Engine Oils
Image credit:

Cold Weather

If you live in a cooler than average climate, these oils may be your best options:

  • SAE 10W-30: The number “10” indicates that this oil is thinner and therefore can flow more easily in cold conditions. I recommend the STP 18588 4 Cycle Oil
  • SAE 5W-30: This oil is even thinner than the previous and so can perform well in extreme cold conditions. If you live in an icy climate, it could be your best option. The Briggs & Stratton SAE 5W-30 is an excellent option in this category. 

Small Engines

If you live in a hotter climate or have a small lawnmower, you should opt for SAE 30 type oil. I recommend the STP 4 Cycle SAE-30 Oil. It performs well in warm climates and has a specific design for smaller engines. It is also one of the most affordable options. 

Commercial Engines

15W-50 is your best option if you work commercially with your lawnmower. It can work across a variety of temperatures and can also withstand ongoing and heavy use. 

Synthetic Oil

Synthetic oil is viable for most conditions. It is very slippery and so it works well as a lubricant. Compared to other oil types, it also performs well in more extreme temperatures. However, it can be more expensive and less efficient than conventional oil. 

When Should You Change Your Lawn Mower Oil?

You should change your lawn mower oil after approximately 50 hours of use. If you have a brand new mower, I recommend changing it for the first time after five hours. However, you can also check the levels periodically to see if the oil needs changing. 

How To Change Lawn Mower Oil

Here is how to change your lawn mower oil:

  1. Let the engine run continuously for a few minutes and then turn it off.
  2. Pull out the spark plug and find the oil drain plug.
  3. Loosen the plug and allow the oil to drain.
  4. Tighten the plug again.
  5. Switch the engine filter for a new one. 
  6. Pour in the new engine oil, without exceeding the maximum capacity
  7. Switch on the engine and look for leaks. 

This video shows you how to do it. 

YouTube player


Can You Use 4 Cycle Oil In A Lawn Mower?

Four-cycle oil is suitable for four-stroke lawnmower motors. Larger mowers usually have this engine type, although you should check your product manual. For these kinds of lawnmowers, SAE 30 is often a suitable choice. However, a two-stroke motor will need a different type of oil. 

Can You Use Regular Motor Oil In A Lawn Mower?

If your mower has a large, four-stroke engine, it may handle using regular motor oil. However, motor oil has a different viscosity to mower oil and can get stuck in the mechanisms. It is usually better to buy lawn mower-specific oil. 

Can You Use 5W 20 Oil In A Lawn Mower?

5w20 oil is not usually a good option for lawn mower engines because it is so thin and it may not adequately lubricate the engine parts. This may damage your lawnmower or cause it to overheat. 

Is SAE 30 The Same As 10W30?

SAE 30 is not the same as 10W30. The “W” in the acronym stands for winter and means that 10W30 has a viscosity of SAE 10 at lower temperatures and 30 at higher temperatures. SAE 30 is a simpler oil type that does not change in viscosity. 

Can You Put SAE 30 In A Lawn Mower?

SAE 30 is one of the most common oils for lawn mowers. It works best with small engines and performs well in warmer temperatures. However, it is not the best option for large mowers or cold climates. 

Choosing The Correct Oil For Your Lawn Mower

In conclusion, there is no single answer to the question “what kind of oil goes in a lawn mower?” The suitable oil depends on the climate where you live, your lawn mower size, and whether or not you will use it commercially. 

By choosing the correct oil, you allow your lawn mower to lubricate and work more effectively for the long-term. If you want to know more about learn more lawn mower performance, check also themowerpoint.

Please comment if you have any further questions about the right oil for your lawn mower. 

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About The Author

Brett Jones

Brett's the kind of guy you'd never peg as having such an amazing yard. He's shy and private, avoiding social media and the spotlight. By day, Brett works quietly as an electrician technician, helping folks with wiring and repairs. But get Brett home to his place in Raleigh, where Nadya's always dreaming up new landscaping ideas, and you see another side of him. Brett happily rolls up his sleeves to transform their modest backyard into a lush, cozy oasis. The yard's really a labor of love for them, a place to unwind on weekends, entertain friends, and make cherished memories together. Nadya might come up with all the creative concepts, but Brett's the one ensuring each vision comes to stunning life. They make a great team, even if Brett's content to operate behind the scenes. At heart, Brett's a simple man who finds purpose and joy in small things. Puttering in their garden under the sun or cooking out back in the evenings - these are the things that fulfill him. Brett cares deeply for crafting a space ideal for intimacy, nurturing a life well-lived away from fanfare. Follow him on Twitter.

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