What Oil Type Should I Use For My Lawn Mower?

First let the engine cool down. Wear work gloves to protect your hands. Now, let’s get started...


Disconnect the spark plug wire from the spark plug. Pivot the cable clip up and release it from the mower handle.

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Every lawn mower requires the correct sort of engine oil used in the right way. Learn here about various lawn mowers and the oil they need.

Why Oil For Lawn Mowers Matters:

Just like other internal combustion engines, lawn mower engines require oil to run. Even simple engines have many moving parts that are often designed to have to work at very high temperatures and speeds. That's why oil's cooling and lubricating action is essential. Without oil, the engine of your lawn mower would quickly overheat, seize up and get ruined and useless.

Lawn Mower Oil Types :

Motor oil is made in various different grades based on viscosity and oil's properties at different temperatures. Most lawn mowers have engine types known as four stroke. That means they burn gasoline as it comes from the service station pump but mowers also need motor oil to be separately added to the engine's crank case.

A common motor oil grade is 10W30 which is suitable for many lawn mowers. Your owner’s manual will inform you the exact type required. However, in almost all cases 10W30 is the correct oil grade for four-stroke lawn mower engines.

In general any brand of motor oil suitable for trucks or cars will work well in your lawn mower. All reputable oil types include a service rating in addition to its viscosity rating. Check for oil that is designated SF, SG, SH, SJ or higher.

Some lawn mowers are equipped with two-stroke engines and these need oil in a different way compared to four-stroke engines. Two-stroke engines burn gasoline and oil at the same time. When it comes to lawn mowers, two-stroke oil is mixed together with the gasoline before going into the tank.

Mixing ratios of oil to gas vary but usually range from 30:1 (4-1/4 oz. of oil to one gallon of gas) to 50:1 (2-1/2 oz. of oil to one gallon of gas). Your owner’s manual will list the mixing ratio of gas to oil.

Two-stroke engines for lawn mowers are becoming less common because of emission regulations but there are still plenty around. So how do you know if you have a two-stroke or a four-stroke engine in your lawn mower? The answer is your owner’s manual which will certainly be the best guidance.

How To Select The Correct Lawn Mower Oil :

Some say that expensive "small engine oil" is the only type to use in your four-stroke mower engine. But that is not really true because standard engine oil made for trucks and cars is the highest quality available today and it works fine with all four-stroke engines.

If yours is a two-stroke engine, any two-stroke motor oil made for air-cooled engines such as chain saws, water pumps and weed eaters will work just fine in your two-stroke lawn mower engine.

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

Should I Use Synthetic Oil For My Lawn Mower?

Synthetic oils are superior to lubricants made from crude oil and your lawn mower engine may well last longer if you use synthetic oils. According to Briggs and Stratton, which is one of the world’s largest manufacturers of small engines, using synthetic oil doesn't alter required oil change intervals.

Regular, non-synthetic oils work well too. I have used non-synthetic oil in some of my small engines for 30 years and those motors still start and run as if new.

When To Change Or Add Lawn Mower Oil :

Only four-stroke lawn mower engines have oil that can be checked and changed. You should check the oil level and top it up if necessary before starting each mowing day.

If your four-stroke lawn mower engine is new, it's recommended to change the oil after the first three to five hours of use. As parts of a new engine initially wear, the internal movement of the parts releases tiny metal filings into the oil that cause excess wear if not removed.

Change the oil of a broken in lawn mower at least once per season or not more than every 50 hours of use. Your mower's manual will list the amount of oil needed. However you will be fine following the dip stick or oil level mark that is part of every four-stroke lawn mower engine.