Lawn Mower Oil Type: What Kind Suits My Engine?

If you are new to gardening or landscaping then you are probably wondering what the best oil for your lawn mower is. With so many options available in the market today the best Lawn Mower Oil choice is bound to confuse you.

Selecting the wrong oil could be costly as it may damage your mower. Worry not because we have explained the details of all the available lawn mower oil types and what makes one the best for your engine.

Why Does Your Mower Need Oil?

Lawnmower oil

Like any of your power tools, lawn mowers also need oil to function. The oil lubricates the various engine parts which in turn reduces wear and tear caused by friction.

However, not all engine oils will work for your mower? The difference lies in the viscosity or the speed at which the oil flows under varied conditions.

Understanding The Lawn Mower Engine Oils

There are several factors that you need to consider before you purchase lawn mower oil. Understanding the oil that is best for your mower ensures that your machine performs optimally and also sees an increase in its life span.

Again there is synthetic and conventional oil that perform different roles. Educating yourself on these ensure that you do not end up making the wrong selection.

1. Motor Oil

Many lawn mower owners use regular motor oil for their engines. However, there are better alternative options available today.

  • Four-stroke engine 

Perfect for large mowers the four-stroke engine is commonly used in riding mowers. The four-stroke engine is the same that you find in large vehicles. These pump oil through the sump and then return the oil to the sump.

If you have a four-stroke engine then you can use the motor oil without a doubt. However, there are chances that your mower may have special requirements on the kind of motor oil to use. There could be specifications in additives or viscosity so you need to understand what a safe bet for your mower is.

2. Small Engine Oil

Small engine oil offers protection and additives that are used in varied operating conditions. Your mower may sit for many days and weeks without getting used or it may have been used in a dirty and dusty environment and then placed in storage.

Using a small engine oil of high quality that comes with high film strength and can cling on to the dirt, lets your lawn mower run for many years. And the best thing is that the small engine oils come in many viscosities.

Before you choose to use small engine oil of a particular viscosity always refer back to the owner’s manual that will specify the type and the viscosity of oil that you should use.

  • Two-stroke engine 

Two-stroke engines are perfect for smaller mowers because they do not have any separate system of lubrication. The oil gets mixed with fuel and then it passes through and lubricates the engine. The oil gets burnt along with the fuel.

Here since the fuel and oil mix together you need to mix them in a particular ratio which usually will be an oil: fuel ratio of 32:1 or 50:1.

3. Synthetic Oil

Synthetic oil is better than the conventional engine oil varieties as they are more refined and offer improved performance. The base stock of the oil goes through several chemical refining processes which remove impurities. The final output is thus more consistent.

The conventional oils on the other hand follow a less intensive refining process that leaves back imperfections and leads to engine wear and tear.

Understanding The Lawn Mower Engine Oil Numbers

Depending on the size of your mower and the climate where you reside there are varied engine oil options to choose from. Each has a separate code with letters and numbers that indicates how the oil will perform under varied conditions.

SAE or the Society of Automotive Engineers developed a scale to measure different kinds of oils. The number describes the oil flow. The lower is the number, the oil flows best in low temperatures.

The multi-grade oils perform in high as well as low temperatures. These have two numbers that are separated with a W which stands for winter. The number that is written before the W determines the viscosity of the oil at a low temperature. The number written after the W shows the performance of the oil at a high temperature.

Lawn Mower Oil Type

Not all the oils are made equal and it pays to know the subtle differences between them. The older oils were classified only based on grade and weight. However, the new oils have viscosity added to it.

#1. SAE 30

SAE 30 Engine Oil
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This is single-grade oil or straight-weight oil and has a viscosity rating of 30. The oil is safe for air-cooled and small engines typically best for the old mower models.

#2. SAE 10W-30

SAE 10W-30Engine Oil
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This is multi-grade engine oil that works efficiently in the hot as well as the cold temperature.

#3. SAE 5W-30

SAE 5W-30 Engine Oil
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It is a multi-grade engine oil variety, has a low viscosity, and flows well in a cold climate. It also protects the engine from heat.

#4. Synthetic SAE 5W-30

Synthetic SAE 5W-30 engine oil
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This is synthetic mower engine oil that works well in cold as well as in warm climates. The oil is more stable across varied temperature range in comparison to the traditional oil.

How to pick the Right Engine Mower oil?

Check your operator manual to see if motor oil or small engine oil is recommended by the manufacturer. Also, make sure to check the recommendation for viscosity.

  • If you live in a warm area that has over 40º F temperature then choose the SAE 30 oil which is ideal for hot climates and small mower owners. The oil is also an affordable option
  • If you live in an area that experiences a wide temperature range between 0-100º F then choose to use the SAE 10W-30 oil. The number 10 is an indication that the oil is thin and can easily flow even in a cold climate.
  • For cold areas that experience below 40ºF as well as high temperatures of over 120ºF choose to use the SAE 5W-30 synthetic oil. This oil is thin and is best for extremely cold temperatures.
  • For a commercial lawn mower and if you need to mow several areas at one time use a heavy-duty 15W-50 synthetic oil. The oil can work across a range of temperatures and also withstands heavy and ongoing usage.
  • Synthetic oil is a viable option in various conditions. It is slippery and a great lubricant that performs even in extreme weather. It is however more expensive than the traditional engine oil.

Understand the Service Rating of your Mower Engine Oil

service rating of your mower engine oil

Motor oils come in varied grades based on their viscosity. Any oil brand that works for your car and truck will work for your mower.

All the reputed oil manufacturers include a service rating along with viscosity. Let us understand the ratings further. You need to look for oil that is designated with an SF, SG, SH, SJ, or a higher grade.

1. Single Grade Oil

A single grade oil is one without any additives used to change its viscosity and it is used only when the temperature is high say 100°F.

2. Multi-Grade Oil

A multi-grade level oil makes use of additives to give it better viscosity and to work in a range of temperature conditions.

3. Synthetic Blend Oil

This is a mixture of synthetic and regular oil along with additives that perform at cold temperatures. It costs less than the full synthetic oil.

4. Full Synthetic Oil

This is a lubricant created artificially and offers a range of benefits perfect for commercial and high-performance engines.


Right Oil for your Lawnmower

Choosing the best oil for your lawn mower engine is complicated. And this is because there is no definite answer to this question. Suitable oil is one that works well in the climate that you live in, is perfect for the size of your mower, and is determined based on whether you use the mower for personal or commercial use

The right oil will ensure that your mower is lubricated and works well in the longer run. Always check the owners’ manual to understand the best oil for your engine.

To increase the efficiency of your mower, change the oil after 50 hours of mower usage and if for the first time then after five hours. Also, make it a practice to check the oil levels periodically to see if the oil needs to be changed.

Also read: The different types of lawn mowers available in the market.

About Jennifer Igra

Growing up in Brooklyn, New York City known for it’s green gardens. Jennifer, a 30 year old gardener and green living fanatic started Igra World to share her gardening journey and increase gardening awareness among masses. Follow Igra World to improve your gardening skills.

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