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Like all powered equipment, your lawn mower has an engine with moving parts that need oil to run smoothly. The engine or motor oil provides the lubricating and cooling action for the engine to work efficiently. Over time, the motor oil that came with the machine gets dirty and gunky, and you may have to replace it with an aftermarket oil to extend the life of the engine.
Since most lawn mowers don’t come with extra motor oil bottles, it can be a bit hard to determine the best replacement, especially if you can’t find the factory engine oil that came with the machine. Well, we are here to help you choose the best lawn mower oil on the market that’s ideal for your equipment’s engine.
The Best Lawn Mower Oils
Protect your lawn mower or tractor’s engine from friction and overheating with the STP 4 Cycle Oil Formula. It’s formulated with anti-wear technology, which provides a thin lubricating layer to prevent friction. It also includes antioxidants that prevent a thermal breakdown from high operating temperatures.
The formulat also includes corrosion inhibitors that keep the metal parts in good condition when the lawn mower is in storage. This in turn helps to prolong the oil drain period and keeps the engine in good condition for longer. It’s rated with an SAE 30 viscosity grading, so it’s most reliable in a hotter environment, and you need to drain it during the cold season. It’s also a detergent oil and will clean and control carbon deposit build-up in the engine’s critical components to maintain efficiency.
High-end detergent oil
Compatible with standard four-stroke engines
- Weight32 ounces
Prevents premature engine wear and corrosion
Cleans and lubricates the engine
Reliable in hot weather
Resists thermal breakdown
Not for extremely low temperatures
Only for four-cycle engines
Only for gas engines
If you are looking for high-quality OEM fluid for Briggs & Stratton equipment, then the SAE 30 is the right engine oil. It’s formulated for air-cooled, four-cycle engines in small lawn mowers. It comes in an ergonomic 18-ounce bottle that’s ready to use, so you can pour it directly to the top of the engine.
It’s also a detergent oil and helps rid the engine of harmful deposits. The oil remains fairly stable within an operating temperature of 40 to 100-degrees Fahrenheit — it’s dependable when the ambient and operating temperatures run high, but you have to drain it before the cold season. All these properties and an affordable price tag will save you a lot of money in oil changes in the long run.
SAE 30 grade
Designed for four-cycle engines
- BrandBriggs & Stratton
- Weight18 ounces
Reduces friction and keeps the engine cool
Helps reduce your engine maintenance costs
Ideal for almost all types of engine-operated lawn mowers
Great OEM oil replacement
Can’t be used in cold temperature
Not compatible with two-stroke engines
Only available in small 18- or 3-ounce bottles
John Deere is one of the big names in the lawn care industry, and it offers an economic four-pack of 32-ounce bottles that are designed for gas engines in lawn and utility equipment. This 10W-30 engine oil is of high-grade quality and is formulated for four-cycle engines. The oil is made through a high-refining process, so it produces fewer emissions than most engine oils. It helps protect the engine parts during hot or sunny days.
Also, the oil includes additives that improve its shear stability, so it can retain its properties even under high stress. It’s used up faster when operating above 80-degrees Fahrenheit, but even then it resists viscosity change even with an increase in operating temperature. Besides that, you can expect it to provide consistent lubrication from engine start-up and during operation.
Designed for gas engines
High shear stability
10W-30 SAE grade
- BrandJohn deere
- Weight32 ounce
Reduces harmful emissions
Provides consistent engine lubrication
Resist high-temperature breakdown
Safe to use all year round
Only for gas engines
Not compatible with older two-stroke engines
Higher oil consumption at higher temperatures
Husqvarna is a Sweden-based manufacturer of power equipment for outdoor use. It also designs care products for most of its equipment. The SAE 30 Premium Oil is a synthetic blend motor oil that’s designed for small, walk-behind, Husqvarna lawn mowers that use air-cooled, four-stroke engines.
It provides optimal lubrication at higher temperatures to prevent engine wear and scuffing. It also resists thinning or break down during harsh operating conditions (including hot weather or high operating temperatures) to promote low oil consumption. However, just as with many SAE 30 motor oils, its cold temperature performance is a bit subpar, so it’s best to use it as a seasonal lubricant. Besides that, it meets and exceeds API Sj specifications.
SAE 30 grade
Designed for four-stroke engine applications
- Weight32 ounces
Prevents premature engine wear
Provides optimal lubrication during harsh operating conditions
Meets engine manufacturer’s safety recommendations
Can improve fuel efficiency
Leans on the expensive side
Subpar cold temperature performance
Only available in 32-ounce bottles
If you have a Honda lawn mower, then you are going to want the Honda 10W-30; it’s a standard OEM product for genuine Honda equipment. It’s a multi-grade oil with an SAE grade of 10W-30, the oil will remain viscous at a temperature range of about zero to 100 degrees Fahrenheit. This means that you will have no trouble starting the engine on cold mornings. The oil may be used faster, but the faster warm-up is a welcome advantage during cold weather.
Another benefit is, the oil is formulated with polymers that improve its sheer stability so it can be used throughout the year. It will maintain its properties even when the lawn mower is in seasonal storage. Additionally, the polymers improve the lubricity to prevent fast engine wear.
Genuine Honda product
Designed for four-cycle engines
- Weight12 Ounces
High shear stability
Lubricates the engine
Less frequent oil change
Resists wear and corrosion
Only formulated for Honda engines
Gets consumed faster during cold starts
Made specifically for older models of Toro and Lawn-Boy lawn mowers with two-cycle engines, this engine oil will help keep the engine running efficiently for a long time. It’s a synthetic blend oil that’s designed with a unique composition featuring fuel stabilizers that resists thermal or chemical breakdown during high operating temperatures, or when the oil is in storage.
It also includes special cleaning additives that help to clear deposit buildup that drains the engine power, and also prevents further buildup of harmful deposits. You will appreciate that the oil mixes easily with fuel regardless of the weather conditions. You have to add it directly into the fuel, and this is why it’s not suitable for four-stroke engines, in a 32:1 mixing ratio.
Synthetic blend oil
Designed for older two-cycle engines
Includes a fuel stabilizer
- Weight8 ounces
Doesn’t breakdown during prolonged storage
Maintains its viscosity at high temperatures
Contains ashless additives for cleaner emissions
Long shelf life
Only formulated for Toro and Lawn-Boy lawn mowers
Not ideal for four-stroke engines
Might ship as a lower quantity
Poulan Pro offers an SAE 30-grade engine oil that offers long-lasting protection to most outdoor power equipment with four-stroke engines. It comes in a 20-ounce bottle and will come in handy for occasional oil refills. The SAE 30 grade means that the oil maintains its viscosity and resists mechanical shearing when temperatures go above 40 degrees Fahrenheit, but isn’t the best choice for low-temperature conditions.
It’s formulated with corrosion inhibitors that resist oxidation to prevent rust and corrosion on the metal components. This will help to keep the engine in good condition for longer so you can get the most out of your lawn mower. Also, it meets multiple engine manufacturer’s recommendations, including API SJ standards.
SAE 30 grade
Designed for four-stroke, air-cooled engines
Includes corrosion inhibitors
- BrandPoulan Pro
- Weight20 ounces
Can be used on any four-stroke lawn mower
Great for warm weather
Resists thermal breakdown even under harsh conditions
Prevents rust and corrosion
Only available in 20-ounce bottles
May freeze when temperatures dip below zero degrees
Only compatible with four-stroke engines
Kohler Industries offers a synthetic blend motor oil with an SAE grade of 10W-30 that’s formulated for Kohler engines. It remains reliable in a wide range of operating temperatures, though it may thin faster when operating temperatures go beyond 80 degrees Fahrenheit. Despite that, it can provide easy engine starts during cold weather. Generally, the oil is designed to lubricate the machine parts to reduce engine noise and to promote smooth and quick movement. This translates to minimal energy loss and less frequent battery drain.
Additionally, the oil is formulated with heavy-duty zinc, phosphorus, and molybdenum additives to improve its anti-wear properties and its stability in harsh operating conditions. It also prevents foaming in fuel and dissolves varnish and sludge that accumulates on the oil filter. You can use it on both gas and diesel engines.
Synthetic blend oil
Includes zinc additives
SAE 10W-30 grade
- Model25 357 06-S
- Weight1 quart
Provides year-round use
Dissolves varnish and sludge
Highly penetrative for enhanced lubrication
Reduces metal wear and corrosion
Evaporates at temperatures beyond 80 degrees Fahrenheit
May ship in substandard packaging
A bit expensive
Best Lawn Mower Oils Buying Guide & FAQ
Whether you have a push mower, a tractor-pulled mower, or a zero-turn lawn mower, it's important to ensure that you change the engine oil so the engine can run smoothly. This will help to reduce the time and effort you take when mowing the lawn. Depending on the type of motor oil you use, you should schedule an oil change at least once a season.
With the market flooded with a plethora of motor oils for automobiles and power equipment, it can be a bit tricky to find the best engine oil for your lawn mower. For this reason, we have come up with a simple buying guide that you can follow to keep you from buying an engine oil that's not up to snuff.
Why Do You Need Lawn Mower Oil?
A lawn mower’s engine is made up of metal parts that are in constant contact with each other. Motor oil creates a thin lubricating film on the moving parts, which helps to reduce friction and prevent wear. This leads to less fuel consumption over time since the metal parts are moving more efficiently.
Synthetic oils come with additives that help prolong the engine’s life. This includes corrosion inhibitors that protect the engine parts from wear and tear caused by oxidation and detergents that dissolve impurities that travel to the oil filter so you don't have to change your oil filter as frequently.
- It keeps the engine from overheating.
- It optimizes engine performance and efficiency.
- It lubricates the moving parts for smooth movement.
- It keeps the engine in good working condition for a long time.
- It prevents engine damage caused by contaminants.
- The fuel burns cleaner.
Different Kinds of Lawn Mower Oil
There are three types of lawn mower oil: Conventional, fully synthetic, and synthetic blend. It can be a bit difficult determining the best oil to use, but knowing the benefits offered by each type will help you make a better buying decision. Here's an in-depth look into the types.
Conventional oil is derived from refined crude oil. Though it doesn't provide the same extended benefits as synthetic oils, it's not considered to be a lower-grade alternative since it can lubricate and protect the engine parts even at high temperatures. However, it tends to be thicker and sludgier than synthetics.
Most conventional oils on the market are inexpensive since they don’t come with advanced formulations. Therefore, buying conventional oil is more economical if you need to change your lawn mower oil more frequently.
Fully synthetic oil is an artificial type of oil that is made by rebuilding petroleum molecules so they can have better properties than conventional oil. Synthetic oils offer the highest level of protection since they're mixed with a variety of additives that help to improve the performance of the oil. They come in different formulations since manufacturers use different types of additives for their products.
Ideally, fully synthetic oils help the engine to last longer and run cleaner. They also have a longer shelf life and don't need to be drained out as frequently as conventional oil or synthetic blends. For this reason, they typically cost more than the other options.
Semi-refined oils or synthetic blends are made from a combination of conventional oil and a synthetic base so you get the benefit of both oils while paying a reasonable price. There isn't one specific way of creating synthetic blend oil since different manufacturers take different approaches to formulate it. But the general idea behind the formulation is to create an oil that outperforms and outlasts conventional oil.
Despite having a synthetic base, it can't be used interchangeably with fully synthetic oil since they don't have the same molecular size or properties.
What to Consider When Buying Lawn Mower Oil
There are still a few more considerations you need to make besides choosing the best type of oil for your lawn mower. This mostly boils down to getting the right formulation for the type of engine you have, while considering the ambient temperatures or weather conditions in your region. Below are some key considerations.
The lawn mower manufacturer typically recommends the type of motor oil you should use for the specific type of engine your lawn mower has. You can get this information from your owner’s manual. You can either have a two-stroke or a four-stroke engine. A two-stroke engine, though not as popular due to emission regulations, burns gas and oil in the same compartment. It can use any standard motor oil that's compatible with two-cycle engines.
In contrast, a four-stroke engine has a different compartment for the oil and gas and burns it separately. While most can use standard motor oil, you need to get oil that's formulated for four-cycle engines for improved efficiency.
Your lawn mower’s oil consumption rate and efficiency are largely affected by both the ambient and operating temperature. You need to consider how hot your lawn mower’s engine gets, and have an idea of the highest and lowest temperature to expect in your region. This will help you determine the best SAE grade for your motor oil. You can either use single-grade (straight-weight) or multi-grade oil.
Single-grade oils are best used in warmer temperatures, and cannot be used with viscosity modifier additives. The most common grades of single-grade oil include 0W, 5W, 10W, 20W, 20 30, 40, 50, and 60. Multi-grade oils are formulated with viscosity improver additives and are best used in areas where the temperature ranges between 0 to 100 degrees Fahrenheit. Some grading examples include SAE 10W-30, 10W-40, or 5W-30.
If you're buying synthetic oil or synthetic blends, prioritize formulations that are rich in additives and stabilizers. A few additives to look out for are anti-corrosion and anti-wear additives that help to keep the engine in top shape. Also, choose formulations with detergents so you can keep your engine running clean with minimal emissions.
Stabilizers help to keep the oil from breaking down when it's used in harsh conditions, high operating temperatures, or when it's in storage. This helps to improve the longevity of the oil so you can use it for longer without draining it.
Best Lawn Mower Oils FAQ:
Even after acquiring the wealth of information that you now have, we recommend that you always read the label, and pay attention to the manufacturer’s do’s and don’t. If you happen to have further questions, we hope that the answers we’ve provided to commonly asked questions by buyers cover most of your concerns.
Q: How much oil goes in a lawn mower?
A: It depends on the size of the engine. Large engines can take up to 25 ounces while smaller engines need about 15 ounces. You will find the information on how much engine oil your lawn mower needs in the owner’s manual.
Q: What type of oil goes in a lawn mower?
A: Lawn mowers use either two-stroke or four-stroke engine oil, which is formulated to mix with the fuel. The oil type can either be conventional, fully synthetic, or a synthetic blend.
Q: Is there a difference between lawn mower oil and car oil?
A: There isn't a big difference since you can use automobile oil in a large lawn mower with a four-stroke engine so long as the formulation is tailored for the engine’s specification. For instance, if you have an automobile oil that's for gas engines, you can also use it in a lawn mower that uses a gas engine. However, automobile oil can be overkill for small lawn mowers.
Our Top Pick
The STP 4 Cycle Oil Formula earns our top spot because it's a great small engine lubricant that flows smoothly and reduces friction. It helps to reduce engine wear and tear and also cools the metal components. Also, it’s compatible with almost all lawn mowers that use four-stroke engines.
If you are looking for a cheaper alternative to the STP 4 Cycle Oil Formula, you can opt for the Briggs & Stratton SAE 30W Engine Oil. It contains additives that prevent oil breakdown and cleans the engine for optimal efficiency. It also prevents engine wear.
Motor Oil - Wikipedia