Types of Oil for Your Lawn Mower

A lawn mower has various moving components inside it that require proper lubrication and protection so that it can function correctly under such high temperatures, pressure, and speed. Engine oil provides the mower with the lubrication and rust protection it needs to operate smoothly.

Choosing the correct engine oil can be a difficult task as there are thousands of different types of oil produced by various companies in the market. Understanding the different oil types will help you sort it out when it comes to choosing the Best types of oil for your lawn mower.

Among these various types of oil, you must choose the correct one based on the climate, the engine, the manufacturers’ guidelines, and the frequency of usage. Choose carefully as difficult problems such as overheating, stalling, piston getting damaged, cylinder walls getting damaged, and so on can arise because of the wrong engine oil.

What Are the Different Types of Oil for Your Lawn Mower

There are different types of oil in the market which are categorized based on their production and their purposes. The most common kinds of oil that are used in lawnmowers are discussed below in detail.

Conventional Oil

Conventional oil has a base oil which is a 100% mineral oil obtained through the refining process of crude oil. Crude oil is distilled and cleaned to create this high-quality base oil but the molecules remain substantially unchanged.

Conventional oils are the most affordable and readily available oils in the market. Although they do not perform as well as their synthetic counterparts, they can still protect and lubricate the parts on your mower without failure. Use the recommended viscosity mentioned in the user’s manual. Usually, lawnmowers use motor oil of 10W30 or 10W40.

Synthetic Oil

Synthetic oils are synthesized by creating new base oil components. Unlike conventional oils, synthetic oils are created through substantial changes in their molecular structure. A full synthetic motor oil gets all of its base oil from synthesis.

Synthetic oils are usually better in performance than conventional oil but they are also more expensive. Synthetic oils perform better in extremely low or extremely high temperatures. They also provide higher thermal stability or heat resistance and possess better oil burn performance. 5W30 and 15w30 synthetic oil provide good protection for your mower.

Synthetic Blend Oil

Synthetic blend oil, semi-synthetic oil, or part synthetic oil has a base oil that is created by combining synthetic and conventional base oils. There are no standards for the ratio between them so it’s usually unspecified.

Synthetic blend oil works better than conventional oil as it improves low-temperature performance, provides higher heat resistance, and helps to improve motor oil stability. SAE-10W30 is one of the best semi-synthetic oils.

High-Mileage Oil

The base oil is mixed with additives and seal enhancers to create high-milage oils. These oils were specifically created to reduce leaks and increase the performance of cars. Most of the time, these oils are used in cars that have run for 75,000 miles or more.

Although these oils are not created for lawnmowers, they can still be used. High-milage oils such as SAE 10W30 synthetic blend motor oil can be used in 4-stroke engine mowers. Be sure to check the instruction manual for assurance.

Bio-Based Oil

Bio-based oils get their base oils from plants and animals such as vegetable oils and animal fats. Bio-based oils are also refined like mineral-based oils or conventional oils. Biodegradability makes bio-based oil the best choice for any environment-conscious individual.

Various brands such as Aspen, Motul, and Agealube have bio-based oils available in the market for lawnmowers. Match the recommended viscosity to ensure that the oil suits your mower’s engine.

How to Choose the Right Oil for Your Lawn Mower

You must consider certain factors like the manufacturer’s recommendations, engine type, temperature, intensity of usage, and budget constraints when you are choosing the perfect engine oil for your lawnmower. Be mindful while choosing the correct oil as it will affect the performance and longevity of your lawnmower.

Manufacturer’s Recommendations

Manufacturer’s recommendations are the first and foremost things to consider while choosing the correct oil for your lawn mower. Manufacturers will specify the viscosity and quality of the engine oil in the instruction manual.

Go through the instruction manual thoroughly to find out which oils they recommend and which oils they warn against using in their lawnmowers. Matching the viscosity or the numbers will be adequate as various brands will have that exact recommended oil.

Engine Types

Engine types also determine the engine oil that can be used in that mower. Mowers usually come fitted with two types of engines. The smaller push mowers are fitted with a two-stroke engine and the bigger mowers are fitted with a four-stroke engine.

Four-stroke engines output more power than two-stroke engines and are used in bigger mowers such as large riding mowers as well as some push mowers. The four-stroke engine has separate compartments for the oil and gasoline. SAE-30 is the most commonly used engine oil for mowers with four-stroke engines. Be sure to check the instruction manual to confirm the oil.

Two-stroke engines are commonly found in smaller and older push mowers. Two-stroke engines have fallen in popularity because of pollution. Two-stroke engines create a lot of smoke and noise while operating. Two-stroke engines are lighter and cheaper but because of environmental regulations, they have largely fallen out of favor.

Two-stroke engines use the same tank to hold gasoline and engine oil and owners have to mix it in exact proportions such as 32:1 or 50:1 depending on the instruction manual. Be extra cautious while choosing the oil for a two-stroke engine mower as the oil needs to be compatible with the gasoline as they will mix.

Climate and Temperature

Temperature is a vital factor to keep in mind while choosing the correct oil for your lawnmower as the viscosity of the oil changes with the temperature. Using the incorrect oil can result in engine failure or worse damage to the mower if the oil is not matched accordingly with the climate and temperature of the area. Some of the most commonly used motor oils with their temperature tolerance are given below.

SAE 30: SAE 30 is suitable to be used in warmer temperatures. This is the most common type of oil used in small engines.

SAE10W-30: SAE 10W-30 functions at varying temperature ranges. Choose this oil if you live in a place where temperature varies a lot by season. This oil helps to start the engine in cold weather but may increase oil consumption.

SAE 5W-30: This oil was specifically designed for very cold temperatures.

Synthetic SAE 5W-30: This is one of the best oils among the other options. This type of oil protects at all temperatures and it also reduces oil consumption.

15W-50: This type of oil is used in mowers that have to undergo a varying temperature range. This type of oil is mostly used in commercial lawnmowers that run continuously for a long period of time.

Frequency and Intensity of Use

Synthetic oil lasts a lot longer than conventional oil as it does not increase in viscosity when it gets exposed to extreme heat. You should choose a synthetic oil if you use your mower very frequently. Conventional oil will burn up faster and the mower will require more engine oil for proper function.

Budget Constraints

Conventional oils cost less than full synthetic or semi-synthetic oils because conventional oils do not undergo sophisticated mechanisms that change their molecular structure. Choose them if you are on a budget constraint. You can also opt for semi-synthetic oils as they are cheaper than full synthetic oils but perform better than conventional oils.

How Often Should I Be Changing the Lawn Mower’s Oil?

You should change the lawn mower’s oil after every 50 hours of usage or once each season. You may need to change it more often if you are using the mower very frequently and the weather and the terrain are considerably rough.

Can You Use Regular Motor Oil in a Lawn Mower?

You can use regular motor oil in a lawn mower if it matches with the manufacturer’s guidelines. Regular motor oils usually work fine with four-stroke engines but it is better to be sure by checking the instruction manual. 

Can I Use 10W30 Instead of SAE 30 in My Lawn Mower?

You can use 10W30 instead of SAE 30 in your lawn mower although it is recommended that you follow the instruction manual correctly.

What Happens if I Use the Wrong Type of Oil in My Lawn Mower?

Various problems such as engine stalling, engine knocking, engine failure, clanking noises, rough idle, loss of power, overheating, black smoke, and so on can occur if you use the wrong type of oil in the lawn mower. Always make sure that the oil you are using is recommended by the manufacturer or matches in viscosity and quality before putting it in your lawnmower.