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What Type of Oil Do You Put In a Lawn Mower? Types, Engines & FAQs

cropped man mowing lawn with lawn mower

Lawn mower engines are small engines that are very different from car engines. Does that mean lawn mowers use different oil than cars? This is a fair question that many people ask themselves while reaching for a bottle of engine oil at the store. Can your lawn mower use car oil? What type of oil should you put in your lawn mower?

The most basic answer is you need to check your owner’s manual, and if you no longer have your lawn mower’s manual, you should search for it online. Most lawn mowers can safely take SAE 30 engine oil. But not all of them can. The type of oil that you can put in your lawn mower will depend on the brand, the size of the engine, your climate, and a few other factors.

divider 7 Consult Your Owner’s Manual

The best advice anyone can give you about the care of your engine is to consult your owner’s manual. Owner’s manuals aren’t fun to read. The font is usually too small and there are a bunch of sections with mundane legal warnings, but all of the information you need to care for your engine will be contained within those pages.

Your owner’s manual will tell you exactly what kind of oil your engine needs as well as how to change it, how often to change it, and troubleshooting for problems that you may encounter when changing your oil. All of that information will be present. All you have to do is look for it.

Most engines can safely run on SAE 30, but why take a risk by guessing? The wrong type of oil doesn’t often harm engines, but in certain circumstances, it could. The safest bet is to simply use the oil recommended by your specific lawn mower manufacturer.

red lawn mower in the field
Image Credit: Piqsels

Different Types of Engine Oil

SAE 30

SAE 30 is one of the most basic forms of engine oil. Many lawn mowers will be perfectly happy to run with SAE 30 in their system. SAE 30 is best for small lawn mowers and people who live in warm climates where it does not freeze very often. SAE 30 is the most common type of motor oil used in small engines.

SAE 10W-30

SAE 10W-30 is a variation of SAE 30. SAE 10W-30 is built for cold weather and will help small engines start in the cold. If you live in an area with harsh winters or cool springs, you are more likely to find people using SAE 10W-30 than standard SAE 30. However, this variation sometimes causes the engine to use more oil than normal, leading to frequent refills.

a black push lawn mower on grass
Image By: rseigler0, Pixabay

SAE 5W-30

SAE 5W-30 is like SAE 10W-30 but a little bit better. SAE 5W-30 offers the best temperature protection at all levels. It offers better protection from high heat and offers enhanced starting capability in freezing temperatures. SAE 5W-30 has the lowest viscosity of oil on this list which helps it behave better in a wide temperature range.

Synthetic SAE 5W-30

Synthetic SAE 5W-30 is the most stable across all temperature levels. Synthetic oil is oil that is artificially produced to have a more stable and balanced composition. Some people avoid synthetic oil because of the cost, but it does offer a few benefits.

Synthetic oil will behave the best in hot temperatures and very cold temperatures. Some synthetic oil blends also have compounds in them that help protect your engine from wear. The biggest drawback is the price which can be a lot steeper than traditional oil.

lawn mower and weeds in the lawn
Image Credit: Pixabay

Two-stroke vs. Four-stroke

The last distinction to make in choosing an engine oil that is right for your lawn mower is whether you have a two-stroke or four-stroke engine. Two-stroke engines are the most common small engine, and they are what make up most typical walk-behind lawn mowers.

However, if you have a riding lawn mower or a zero-turn lawn mower, there is a good chance you have a larger four-stroke engine. Four-stroke engines do better on higher quality oil than two-stroke engines. A four-stroke engine would benefit more from synthetic oil or an SAE 10W-30 than regular SAE 30 oil.

Again, the best course of action is to consult your owner’s manual when deciding on engine oil. Just know that some riding mowers or large lawn mowers will have different care and maintenance guidelines than small two-stroke lawn mowers.

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divider 7 Conclusion

Check your manufacturer’s recommendation before dumping any old oil into your lawn mower. If you must close your eyes and guess on an engine oil, you are probably safe choosing SAE 30 for the vast majority of small lawn mowers. Any oil is better than no oil. An engine without oil will quickly seize up and wear itself down.

Featured Image Credit: Pexels, Pixabay


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