What Type of Lawn Mower Oil Should I Use

Why Lawn Mower Oil Matters

Like all internal combustion engines, lawn mower engines need oil to run. Even simple engines have many moving parts, often designed to work at extremely high speeds and temperatures. This is why the lubricating and cooling action of oil is essential. Without it, your lawn mower’s engine would quickly overheat, seize and be ruined.

Lawn Mower Oil Types

Motor oil comes in different grades, based on viscosity and how the oil behaves at different temperatures. Most mowers have what are called four-stroke engines. This means they burn straight gasoline as it comes from the service station pump, but they also require motor oil to be added separately to the crankcase of the engine. 10W30 is a common motor oil grade suitable for many lawn mowers. Your owner’s manual will tell you the exact grade required, but in almost all cases 10W30 is the right stuff for a four-stroke engines.

Any brand of oil that’s suitable for cars or trucks will work fine in your mower. All reputable oil includes a service rating in addition to a viscosity rating. Look for oil that’s designated SF, SG, SH, SJ or higher.

• Single Grade Oil: A single grade level oil typically without additives to change its viscosity and represents only at higher temperatures (100°C).
• Multi Grade Oil: A multi grade level oil that uses additives to provide better viscosity at a range of temperatures.
• Synthetic Blend Oil: A mixture of regular and synthetic oil with additives to help perform at colder temperatures without the cost of a full synthetic oil.
• Full Synthetic Oil: An artificially created lubricant with a wide range of benefits designed for use in high performance and commercial engines

Some lawn mowers have two-stroke engines, and these require oil in a different way than four-stroke engines. All two-stroke engines burn gasoline and oil at the same time. In the case of lawn mowers, two-stroke engine oil is mixed with the gasoline before it goes into the tank. Mixing ratios of gas to oil vary, but usually range from 30:1 (4-1/4-oz. of oil to one gal. of gas) to 50:1 (2-1/2-oz. of oil to one gal. of gas). The owner’s manual for your lawn mower lists the mixing ratio of gas to oil.

Two-strokes are becoming less common because of emissions regulations, but they’re still around. How do you know if you’ve got a two-stroke or four-stroke engine in your lawn mower? Your owner’s manual is the best source of guidance.

How to Choose the Right Lawn Mower Oil

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Some experts say that more expensive “small engine oil” is the only type of oil you should put in your mower with a four-stroke engine, but that’s not true. Standard engine oil made for cars and trucks is the highest quality available today and it works optimally with all four-stroke engines. Got a two-stroke engine? Any two-stroke motor oil made for air-cooled engines, such those in chainsaws, water pumps and weed eaters, will work perfectly in your two-stroke lawn mower engine.

• SAE 30 Oil: Engine oil best suited for warmer temperatures.  Try top rated Pennzoil SAE 30 Motor Oil.
• SAE 5w-30 Synthetic Oil: Synthetic mower oil good for warm and cold weather use. Try top rated Castrol Edge 5W-30 Full Synthetic Motor Oil.
• SAE 10w-30 Synthetic Oil: Synthetic oil that can help in colder temperatures. Try top rated Mobil 1 Advanced Full Synthetic 10W-30 Motor Oil.
• SAE 15w-50 Synthetic Oil: Synthetic oil typically used for high end and commercial engines. Try top rated Mobil 1 Advanced Full Synthetic 15W-50 Motor Oil.

The best way to mix gas and oil for a two-stroke engine is to put the required amount of oil into your empty gas can, then go to the gas station and fill it up. Before using the mixed gas, give the can a shake to so the oil and gas are properly mixed.

What is Synthetic Oil and Should I Use It In My Lawn Mower?

Synthetic oil is superior to lubricants made from crude oil, and your lawn mower engine may last longer if you use synthetic. Essentially, it is a synthetic lubricant made up of chemical compounds designed to give engines the performance and protection that natural oil may not be able to provide.
According to Briggs and Stratton, one of the world’s largest manufacturers of small engines, the use of synthetic oil does not alter required oil change intervals. Regular, non-synthetic oil works well, too. I’ve used non-synthetic in some of my small engines for 30 years, and these motors still start and run as if they were new.

How Often to Check and Change Lawn Mower Oil

Only lawn mowers with four-stroke engines have oil that can be checked and changed. Tuning up a lawn mower at least once a season, which includes changing the oil, is essential for maximizing fuel economy and extending the life of the engine. Aside from that:

If your four-stroke engine lawn mower is new, change the oil after the first three to five hours of use. As parts of a new engine wear initially, the internal movement of parts releases tiny metal filings into the oil that will cause excess wear if left there.

• Walk-Behind Mowers: Change oil in mower at least once a season or every 50 hours of use.
• Riding Mowers: Change oil in mower at least once a season or every 100 hours of use.

The owner’s manual for your lawn mower lists the amount of oil required, but you’ll do fine following the dip stick or oil level mark that’s part of every four-stroke lawn mower engine.

How to Check Lawn Mower Oil

Before each mowing session, you should check your lawn mower’s oil level and top it off if necessary. To do so:

• Place your lawn mower on a level surface and let it sit idle for a few minutes so that the engine oil can settle.
• Remove the oil cap and wipe the dipstick off with a clean cloth. Put it back into the oil tank and tighten the cap.
• Once again, remove the cap and check the oil level on the dipstick. The level should fall between the “full” and “add” marks. There may be differences in the appearance of these marks depending on the brand of mower you own. Some dipsticks may have only two holes to indicate “full” and “add”, or a cross-hatched pattern. Either way, you want the oil level to be between the two holes or marks. As close to the “full” side as possible without exceeding it.
• Whenever more oil is needed, add it in small increments and repeat this process between each addition to prevent overfilling the engine.

How to Change Lawn Mower Oil

When looking to change the oil in a lawn mower, follow these steps to check off this simple and easy maintenance check.

How Much Oil Does a Mower Take?

Depending on the make and model of lawn mower, push mowers have an oil capacity ranging between 13-1/2-and 22-ounces and riding mowers between 48-and 64-ounces. A mower’s operator’s manual will always list the proper amount of oil recommended for its engine.

What Does SAE Stand For in Oil?

SAE is the acronym for the Society of Automotive Engineers. They are an organization that sets global standards in a variety of fields related to transportation and aerospace. It is the responsibility of the SAE to ensure that automotive oil is standardized throughout the world.

Can You Use Car Oil in a Lawn Mower?

Yes. As previously stated, engine oil made for cars and trucks is the highest quality oil on the market and it works optimally with nearly all four-stroke engines.