Best Oil For Lawn Mowers – Use This Not That…

Why Lawn Mower Oil Matters

All engines require oil to run. Internal combustion engines are designed to have moving parts that work under extreme speeds and temperatures. As a result, lubrication and cooling of oil are necessary to reduce overheating, tear and wear or definite breakdown of the machine. 

Lawn Mower Oil Types

lawn mower oil types

There are two main types of oil for small engines: small-engine oil and motor oil. Motor oils are graded in terms of viscosity and how the oil behaves at varying temperatures. Also, oils will be rated in terms of service and viscosity. 

Also see: Can I Use Car Oil in a Lawn Mower?

Oils that are suitable for vehicles will function optimally in your four-stroke mower. When you set out to get your oil, go for oil with the following designations: SH, SJ, SF, SG, or higher.

  • Single Grade Oil: It does not have additives and changes its viscosity. It represents only at higher temperatures (100¬įC).
  • Multi-Grade Oil: It uses additives to provide better viscosity at varying temperatures.
  • Full Synthetic Oil: It is an artificially created lubricant that has a wide range of benefits. It is designed for use in high-performance and commercial engines.
  • Synthetic Blend Oil: It is a mixture of regular and synthetic oil with additives to help it perform at colder temperatures.

Is It Okay to Use Synthetic in My Lawn Mower?

Synthetic oil works well in a lawnmower.

Synthetic oil is filled with chemical compounds that are artificially made with a mixture of chemically formulated petroleum components. It is much superior to lubricants manufactured from crude oil.

Synthetic oil has better viscosity and deposit control. It also offers better results in terms of wear, and lower temperature fluidity. The chemical compounds provide the engine with better performance and protection from wear, thus giving it a longer life.

Using synthetic oil in your lawnmower extends its overall service life since synthetic oils reduce the chances of engine failure.

If regularly used over the long term, synthetic oils reduce the need for you to replace your lawn mower every so often because synthetic oils increase the chances of longer service life for your mower.

The Best Synthetic Mower Oil I Use Is…

Briggs & Stratton SAE 5W-30 Synthetic Small Engine Motor Oil - 32 Oz. 100074
  • 100% Synthetic SAE 5W-30
  • For Use In All Air Cooled 4-cycle Engines
  • 32 Oz. bottle


Motor Oil for Four-Stroke Engines

Four Stroke Engines

Most mowers are four-stroke engines. Four-stroke engines are reliable and better suited for larger lawn mowers since they power heavy-duty equipment. 

Four-stroke engines are more common in both mowers and riding mowers. In four-stroke engines, gas and oil are kept separate. The engine thus burns gasoline straight as it flows from the service station pump.

However, the engines still need a separate addition of motor oil into the crankcase of the engine. Oil with a grade of SAE-30 is suitable for many lawnmowers. Confirming the engine’s specifications is crucial since the engine could be sensitive to certain additives. 

You should not risk the efficiency of your mower when you could check with the manufacturer’s website or manual for directions.¬†

My Favorite Four-Stroke Oil for Push and Riding Mowers is…

STP 4 Cycle Oil Formula, Engine Care for Lawnmower, Push Mower & Tractor, Bottles, 32 Fl Oz, 18589
  • High quality base oil cushion parts to protect against friction and...
  • Anti-wear technology provides a layer of protection at high...
  • Antioxidants fight thermal breakdown to enhance oil durability
  • Detergents help keep engine components clean
  • Corrosion inhibitor promotes equipment longevity during seasonal...

Small Engine Oil for Two-Stroke Engines

Two- Stroke engines burn oil and gas at an equivalent time. In the case of lawnmowers, oil is mixed with gas before it flows into the tank. The manufacturer’s manuals give specific rations on how to mix oil and gas.¬†Typically, two-stroke engines are on weed eaters, blowers, hedge trimmers, and other handheld lawn tools.

Mostly the mixing ratios are between 32:1 to 50:1. Two-stroke engines are common in smaller and older push mowers. The popularity of two-stroke engines has decreased some over the years compared to four-stroke engines. 

Two-stroke engines produce lots of smoke and are too noisy, which is the likely reason for the decrease in popularity. Any lawnmower is not cheap; the wisest thing, therefore, is to check the manufacturer’s manual for guidelines to know if the engine is a two-stroke engine or not.

These oils have additives that help in getting rid of carbon deposit and also to minimize wear, among other functions. 

When mixing oil and gas for a two-stroke engine, pour a given amount of oil into a can, fill it with an appropriate amount of gas (as per ration), then shake well to ensure it is well mixed.

If you need a good two-stroke oil, go with my pick….

Briggs & Stratton 2-Cycle Easy Mix Motor Oil - 16 Oz. 100036
  • 2-cycle easy mix motor oil
  • Fuel stabilizer that leaves no residue and prevents plug fouling
  • Recommended for toro, lawn boy, ryan and other 2-cycle outdoor power...
  • Oil tip and measure
  • Ashless additives; 16 ounce can

How Do I Choose the Best Engine Oil for My Mower?

When it comes to choosing the right oil type for your mower, your considerations should be based on these particular factors:

  • The manufacturer recommendations
  • The engine type -such as two-stroke engine or four-stroke
  • Oil viscosity
  • Average temperatures of where you live

Oil brands vary in their formulas, with some being regular oil, a mix of regular and synthetic, and some fully synthetic. Let us examine these two:

  • SAE 30 Oil: Suitable for use in warmer temperatures.
  • SAE 5w-30 Synthetic Oil: Best suited for both warm cold weather use.

Briggs & Stratton SAE 30 Grade Mower Engine Oil Review

Briggs & Stratton 30W Engine Oil - 48 Oz. 100028
  • Tested and approved by Briggs & Stratton engineers
  • Warranty certified and recommended in all Briggs & Stratton manuals
  • A high quality detergent oil classified SJ/CD by the API
  • Conveniently sized for today's engines
  • 48 Fl. oz. (1.418 L)

Briggs & Stratton SAE 30 Grade Mower Oil is obviously made from the Briggs & Stratton Company. It is among the best oils for lawnmowers (push, self-propelled, riding, and zero turn mowers) in my and many others opinion.

Most lawnmower engines in the market are four-stroke engines. The Briggs & Stratton SAE 30 Grade Mower Oil specially manufactured the four-stroke engines in mind. The SAE 30 Grade Mower Oil is suitable for use in places with high temperatures (Between 40F to 100F). 

It has a size of 48 oz, which makes it perfect for most outdoor equipment. It has a high versatility even in cases where the mower is used for long non-stop.

Briggs & Stratton SAE 30 Grade Mower Oil is formulated for engines that produce high power and are air-cooled. Briggs & Stratton SAE 30 Grade Mower Oil has been classified by API in the SJ/ CD category because of its high capability as detergent oil.

Briggs & Stratton SAE 30 Grade Mower Oil does not require other ingredients to keep the engine fresh or free from wear and tear. You only need to pour it directly into the tube for the engine oil.


  • It is fairly cheap
  • It is of high quality since it’s genuine OEM oil from Briggs and Stratton.
  • It is compatible with most small lawn engines
  • It is compatible with other outdoor equipment, e.g.tractors.
  • It is SJ/ CD classified by API.


  • It is a bit problematic filling into the gas tank and could cause injuries.
  • It is not suitable for freezing temperatures
  • Its use is limited to four-stroke engines only; therefore, you can not be used for two-stroke engines.


Briggs & Stratton 5W-30 Synthetic  Engine Oil Review

Briggs & Stratton SAE 5W-30 Synthetic Small Engine Motor Oil - 32 Oz. 100074
  • 100% Synthetic SAE 5W-30
  • For Use In All Air Cooled 4-cycle Engines
  • 32 Oz. bottle

The Briggs and Stratton Company produces the 5W-30 class synthetic oil. The company produces varieties that complement different needs in the engine industry.  Briggs and Stratton 100074 5W-30 Synthetic Oil is artificially produced, making it better than common conventional oils.

Briggs and Stratton 100074 5W-30 Synthetic Oil is rated at 32 Oz. Engines in which this oil is used undergo minimal wear and tear in their parts because of their ability to function under hot working temperatures.

The artificial properties of 5w-30 synthetic oil from Briggs and Stratton have so much strength to keep it going for a long time and preserve the engine parts despite the hot conditions during working time.

Briggs and Stratton 100074 5W-30 Synthetic Oil has the following qualities:

  • Better fluidity during low-temperature operation
  • Less volatile, thus easy to contain
  • High thermal stability
  • More significant viscosity-temperature response than many other lawn mower oils
  • Better stability during oxidation
  • Good control of deposition

These properties give the lawnmower more life in terms of reduction in maintenance cost and decreased equipment failure.


  • Less oil consumption
  • The higher stability of the oil against oxidation
  • The oil can work at different temperatures
  • It can work well in shallow temperatures
  • Cold starting of the engine is improved


  • Briggs and Stratton 100074 5W-30 Synthetic Oil are a bit expensive.
  • It may not work in very hot regions, so it may not work well beyond the 100F temperature limit.¬†
  • It does not work with two-stroke engines. It works only for four-stroke engines.

When Should I Change Oil in My Lawn Mower?

Four-stroke engines have an oil level that can be checked, unlike two-stroke engines. It may help if you can top it off before every mowing session.

When your lawnmower is new, it is prudent to change the oil after the first three to five hours of running. Usually, at this time, due to initial internal movements, the engine parts release minute metallic parts into the oil. The parts cause excess wear inside the engine if not drained. 

For a standard running lawnmower, consider the following intervals:

Riding Mowers: Change oil once in a season or at an interval of every 100 hours the mower has been running.

Walk-Behind Mowers: Change oil at intervals of every 50 hours the mower has been in  use or after a season.

The manufacturer’s manual for your lawn mower provides specifications for the amount of oil required. However, keep checking the oil level mark or dipstick for the four-stroke engine to be on the safe side.

Lawnmower oil capacity

Usually, the oil capacity for most riding mowers is either 64oz or 48oz, while the capacity for walk-behind mowers is usually 18oz or 15oz.

How to check the oil level in mowers?

Check Oil Levels in a lawn mower

If you do not have the owner’s manual, follow the following guidelines to check the oil level in your four-stroke lawnmower.

Firstly, dislodge the dipstick cap. You will need to exert some force on the cap, then twist counterclockwise.

Dislodge the dipstick. Wipe it with a rag so that the readings will be visible.

When reinstalling the dipstick, make sure the grooves of the dipstick tube fit perfectly to the teeth on the dipstick cap. 

Reinstall the dipstick cap by twisting the cap in a clockwise manner (You might need to exert some force).

Dislodge the cap again.

Check on the dipstick blade for oil level.

The oil level will be indicated between the full and add marks.
If the oil level is low, consider refilling. Avoid overfilling by pouring a few ounces at a time.  

Allow enough a few minutes for the oil to settle before you recheck the oil level.

How to Drain Old Oil From a Lawnmower

How To Drain Lawn Mower Oil

There are two ways to drain oil from a lawnmower:

  1. How to drain oil using the oil drain

Start by locating the oil drain plug on the underside of the push mower.

Clean the area around the oil drain with an old cloth or rag. This is to prevent any foreign debris from entering the crankcase in the process of draining the oil.

To place a jug or oil pan underneath the oil drain, tilt the mower deck. Add a newspaper to absorb any spillover.

Using a socket wrench, run the plug counterclockwise to allow the oil to drain into your collecting jug or oil pan. When the oil has fully drained, twist the drain plug clockwise and, using a wrench, tighten to secure the drain plug.

 If the mower has an oil filter, you may replace it as well.

  1. How to drain engine oil using a siphon kit

Briggs & Stratton 5431K Oil Extractor Pump, 4-Liter
  • Briggs & Stratton 5431K
  • Genuine Briggs & Stratton Oil Extractor Pump 4L
  • New OEM Part
  • Made in China

 Using your siphon, place one end of its tube into the oil fill hole. Ensure the siphon reaches the bottom of the oil tank. Place the other end of the tube into a stable container. 

Engage the siphon to empty as much of the used oil as you can. You may tilt the engine slightly on its side to help pool the last of the oil. You can strategically move the tube into a position to collect the remaining oil.

 You can also use the siphoning kits to transfer fuel from your fuel container or car directly into the lawnmower’s fuel pump. 

How to refill oil in a lawnmower

1. Dislodge the oil dipstick cap. You will need to apply some force, then turn to open.

2. Check the level of the tank to confirm its emptiness. 

3. If oil addition is required, fill the manufacturer’s recommended amount. 

To avoid messing, use a funnel, or improvise one using paper or use plastic. If it spills over, you may clean up the mess with a paper towel or an old rag.

4. Return the dipstick in its place and screw in the cap. Run the engine for 30 seconds to ensure the oil gets around the engine’s internal parts. 

5. You may dislodge the dipstick again to check the oil level. If it is underfilled, top it up. If you have overfilled, you may have to remove some probably by siphoning. 

Final Thoughts

Lawnmower oil is crucial for the efficient running of a lawnmower. The right choice of mower oil is equally important. The use of the correct type of oil determines how long the lawnmower will serve you. A wrong choice could cost a new mower. 

It is essential to take time to go through the manufacturer’s manual to understand the oil specifications of your lawnmower. Take time to know the best oil for your lawnmower.

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