How Much Oil to Put in a Lawn Mower + Best Oil for Small Engines

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A lawn mower is an expensive equipment requiring attention, maintenance, and care. Apart from the hardware, you should pay attention to its engine oil level. Maintaining the correct level of engine oil is crucial to keep it working properly for a long time. 

But how much oil should you put in a lawn mower? I’ve made this guide to answer just that and other related questions you may have.

How Much Oil Does a Lawn Mower Take?

If you’re a proud owner of walk-behind lawnmowers, it has an oil capacity of 15 oz to 18 oz. Other variations require an oil capacity of 20 oz to 24 oz. The oil should be changed every 50 hours of operation or annually.

removing oil on a lawn mower

Riding mowers, on the other hand, have an oil capacity of 48 oz to 64 oz. The oil should be changed every 100 hours of operation or annually. You may also want to check the engine owner’s manual for guidance. 

Lawn Mowers’ Oil Capacity

There are different answers regarding the oil capacity of a lawn mower. Different variations of lawnmower engines will also lead to different oil consumption and oil capacities. 

How Much Oil Should You Add to Your Lawn Mower?

The manufacturer dictates the amount of engine oil needed. You can also search your engine’s oil capacity online using its make and model number.  

Importance of Maintaining the Right Oil Level

Getting the oil level just right in your lawn mower is a big deal for me and should be for you too. Aside from lubricating the engine, it also allows cooling to prevent excessive heat. 

Additionally, proper lubrication facilitates smooth functioning of the lawnmower, enabling efficient cutting and reducing the chances of stalling or engine failure.

What are the Risks of Adding Too Much Oil?

There are several risks when adding too much oil to the engine. It can lead to engine problems and even produces white smoke over time. 

lawn mower backfiring

Some lawnmower engine do not have an oil filter and an oil pump. These engines use the splash method for lubrication, and adding too much oil harms these engines. 

What to Do if You Added Too Much Mower Oil

If you have added too much oil on your lawn mower, do not worry. I’ve been there, and it’s an easy fix. You can remove excess oil by using an oil pump.  Carefully tilt the mower sideways. This will make the oil slowly move to the drain pan. 

Useful Read: How to Drain Gas From a Lawn Mower Without Siphon

Extra Tip

Allow the oil to settle to the highest full mark before determining whether to add or remove some oil. Trust me, patience pays off here.

What are the Different Oil Types?

There are different variations you can use as engine oils. However, oil recommendations vary with different makes and models of lawn mower engines. Outside temperatures dictate the majority of engine oils. 

Single-grade Oil

Single-grade oil, including SAE30, results in a good working temperature range (40 to 100 degrees Fahrenheit or 100 degrees Celsius). 


Synthetic Oil

Synthetic oils offer the best protection; however, they come with a higher price tag. 

Not only does it lubricate the engine, but the detergent component of the oil cleans and breaks down contaminants due to combustion. Synthetic oils don’t change the oil change respite.

Multi-grade Oil

I would recommend a multi-grade oil for a modern lawnmower engine. The oil is designed to help protect engines that function in higher temperature ranges. 

Best Oil Types for Small Engines

Here are some of my personal oil recommendations for small engines:

Toro lawn mower

Vanguard 15W-50

This oil is normally used in engines that operate in varying temperature ranges.

SAE 5W-30

This oil type can be used in very cold temperatures.

Synthetic SAE 5W-30

Synthetic oil is good for humid, warm, and cold weather usage. 

SAE 10W-30

This oil type can be used in warmer temperatures. 

adding oil to mower

How to Choose the Right Type of Oil

Choosing the right type of oil depends on the engine’s requirements and the temperature of the mower. I always suggest reading the engine’s manual to check oil grades. Oil grades are indicated by the SAE (Society of Automotive Engineers), and a number indicates oil viscosity.

How to Check the Mower’s Engine Oil Level + How to Add Oil

Here is a guide on checking the mower’s engine to see if you have enough oil and adjusting the amount of oil level when necessary. 

Step 1: Place the Mower on a Level Ground

Make sure to place the mower on a flat surface before trying to check the engine oil. Also, make sure that the mower is cold to the touch. You don’t want to get burned

(If you need to use a tool to move your engine, here’s my recommended lawn mower lift for an easy transport.)

lawn mower on the ground

Step 2: Search for the Dipstick

Before adding oil to the lawnmower engine, check if there is already oil in the engine. You may accomplish this by using an oil dipstick. It is usually at the side of the engine. You may disregard this if you are adding oil to a new engine.

person holding lawn mower dipstick

Step 3: Use the Dipstick to Check the Oil Level

In checking the level, remove the cap and clean the area around it to prevent dust from falling into the oil. Then remove the dipstick.

Proceed to clean it using a clean rag, then plunge the dipstick back. Check that the teeth on the dipstick cap match the groove of the dipstick tube.

checking lawn mower oil level

Wait a few moments and proceed to remove the stick once again. Inspect the stick, and you will see the level of oil on it. You will also notice two levels on the stick. The minimum level is marked with “Low” or “L,” whereas the maximum level is marked by the word “High” or “H.”

Low Oil

A low oil level is when the level is below the low-level mark.

Correct Oil Level

The correct amount of oil level of your engine should be in between these two levels. Furthermore, the oil level should not be closer to the minimum or maximum level. 

Too Full

Adding too much oil is not recommended. Overfilled engines will lead to problems and can produce a lot of white smoke. Furthermore, excess oil can lead to engine stalling, so you should also know how to remove oil.  

Step 4: Add Oil

If you need to add oil, allow it to settle before rechecking its level. Make the necessary adjustments to reach the correct level. 

adding oil to lawn mower

Why Do You Need to Check the Oil Level?

Determining the amount of oil in lawn mower is important. The quality and quantity of the engine oil have many functions to help maintain the engine in good condition. Regularly checking and making the necessary adjustments can prevent engine problems. 

I’ve seen what happens when a mower runs low on oil: overheating is almost guaranteed. Once the engine overheats, it can lead to warping, expanding, swelling, and even cracking. Once the metal gets too hot, the priston will weld to the cylinder, which can damage the lawn mower engine. 

My advice would be to maintain the right oil level for lubrication. It will decrease friction among parts, making it last longer. If there is a lack of lubrication, the engine will break apart.

When Should You Change the Mower’s Oil?

In my book, regularly refreshing your mower’s oil is as necessary as the oil itself. With continued use, the engine may get contaminated with dirt or get diluted. Once this happens, the lubricating capacity of the oil is compromised. 

filling lawn mower with engine oil

The type of lawnmower dictates the period when to change the mower’s oil. For walk-behind mowers, I recommend changing the oil every 50 hours of use or annually, whichever comes first. If you’re using a ride-on mower, my guideline would be to aim for an oil change every 100 hours or, again, at least once a year. Your mower will definitely appreciate the attention.

Role of Degreasers + Uses

A degreaser [1] is used to dissolve the oil and grease on the surface. 


Can I use my car oil on my lawn mower?

You can use your car oil on your lawn mower, especially if the oil type is either a 5w30 or a 10w30.

Can I put oil above the dipstick’s maximum level?

It is not recommended to add oil above the dipstick’s maximum level. This can lead to problems and issues for the engine. 

Does the environment affect how often you should change the oil?

The environment does affect how often you should change the oil. Different oil variations have different performances depending on ambient temperature. It is best to change oil according to the environment. 


It’s always best to know how much oil in a lawn mower you should maintain. Not only will this small habit of checking and changing oil make lawn mowers last longer, but it helps maintain optimal performance. 

I hope this article has enlightened you and inspired you to take better care of your lawn mower engine.   

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Robert Johnson is a passionate furniture maker & carpenter, sought after for his knowledge on the craft.
You’ve probably seen his down-to-earth wisdom in USA Today, Bobvila, Family Handyman, and The Spruce, where he has shared commentary and guidance on various woodworking topics.

Robert is the brain behind Sawinery, where he aims to share tips, tricks, and a passion for all things carpentry.

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