Lawn Mower Oil FAQ: 15 Things to Know

What is the right kind of oil for your lawn mower? What does it do, and how often should you change it? Find out these answers to 15 questions about what goes into your engine.

Can You Use Regular Motor Oil in a Lawn Mower?

You can usually use standard SAE 30 motor oil in a lawnmower, which is often used in automobiles. Some manufacturers have specific recommendations for the type of oil used, however, and this should be followed if you know them.

Never use SAE 30 oil in a two-cycle engine, however, since these need special types of lubricants to function.

What is the Best Oil to Use in a Lawnmower?

Unless your lawnmower explicitly tells you to use a different kind of oil, SAE 10W-30 four-cycle motor oils are going to be the best. Several companies make 10W-30 oils that are specifically designed for use in lawnmowers.

Is There a Difference Between Lawn Mower Oil and Car Oil?

Formulations specifically intended for lawnmowers will have a different viscosity and different set of additives, if any at all, than motor oil used in automobiles. That being said, it’s usually safe to use certain types of automotive oil in four-cycle lawnmowers.

Can I Use 10W30 Instead of SAE 30 in My Lawn Mower?

Heavy duty 10W30 oil is safe to use as long as it isn’t loaded with additives and your lawnmower has a four-cycle engine, which most do. Mechanics often feel that 10W-30 oils are superior options.

Can I Use 5W30 Motor Oil in a Lawn Mower?

You can use 5W30 motor oil in lawnmowers. Due to its viscosity-temperature response, some Briggs & Stratton lawnmower engines are designed to work with it.

During cooler months, you can use 5W30 and then switch to 10W30 during warmer ones, especially if you run a commercial landscaping service.

Is SAE 30 the Same as 4 Cycle Oil?

SAE 30 is one type of four-cycle oil, but there are a number of different options. All SAE 30 oils are designed for four-cycle engines.

Both 5W-30 and 10W-30 would also be considered four-cycle oils.

Is it OK to Use Synthetic Oil in Lawn Mower Engines?

It’s generally safe to use synthetic oils in most four-cycle lawnmowers. Using synthetic 5W-30 oil can be a good idea if you use your lawnmower a lot, and some engines specifically call for it.

Can You Use Semi Synthetic Oil in a Lawn Mower?

You can use semi-synthetic oils, but keep your eye out for cheaper store-bought generics that could damage your engine. Look for something that features zinc and phosphorus and calls itself “universal engine oil” on the bottle.

What Happens If I Put 2 Cycle Oil in My Lawn Mower?

Assuming you have a two-stroke engine, your lawnmower would work fine. If you put two-cycle oil in a four-cycle engine, then you can actually ruin the motor completely.

You’d also ruin your engine if you put two-cycle oil in the gas tank on a four-cycle engine.

What Happens if You Put Gas Mixed With Oil in Your Lawn Mower?

Only ever do this if you have a lawnmower that specifically calls for this, such as many two-stroke engine models. If you put a gas-oil mix in a regular four-cycle engine, then you can ruin your lawnmower and you’ll probably have to replace the engine.

How Many Quarts of Oil Does a Lawn Mower Take?

Most lawnmowers will take a little more than ½-quart. Large riding lawnmowers might take up to two full quarts, but you usually won’t find engines that take much more than this on the consumer market.

Where Does Oil Go in Lawn Mower?

Oil goes into a small tank that’s usually mounted along the side of the engine. There’s a designated cap on the top of it that either reads the word “OIL” in big letters or shows you a picture of something like an oil container.

The cap that goes on top of the oil reservoir is often much smaller than the gas cap, so you won’t be able to confuse them.

What Happens if You Don’t Change Oil in Lawn Mower?

Over time, impurities and dirt will start to get mixed up in your oil. Eventually, the motor will probably start to consume oil, which will make the reservoir get low.

Assuming you never even add any oil, the engine will then start to break down since the metallic components will begin to rub against one another. The reason oil is in your lawnmower in the first place is to reduce friction between moving parts.

Can You Add Oil to a Hot Lawn Mower?

Never add oil to a hot lawnmower engine, but don’t add it to a cold one either. Run the engine for a little while and then give it a few moments to cool off so you can change the oil while it’s still warm but not searing hot.

How to Change the Oil in Your Lawn Mower

Turn off the mower and pull the spark plug before you try the following:

  1. Unscrew the oil cap
  2. Check the level using the dipstick or drain plug
  3. Reassemble the parts
  4. Run your mower for around 15 minutes to make sure the engine is warm
  5. Power the mower down again and pull the spark plug
  6. Open the oil cap
  7. Drain the oil into an oil pan, making sure nothing gets spilled out
  8. Fill the oil reservoir with fresh oil
  9. Pour the old oil into the container you just emptied
  10. Replace the oil cap and put the spark plug back on
  11. Fuel your lawnmower up if necessary
  12. Pull the string to make sure it runs
  13. Cap the container of old oil and clean up the pan
  14. Take the oil to a place that accepts old oil for recycling – never pour it down a drain!
  15. Wait for the engine to cool then use your lawnmower like normal