What Kind of Oil do you Use in a Lawnmower?


If you use your lawnmower for some time, you know that maintenance is an important aspect of ensuring a long lifespan. One of the most important engines maintenance practices is the oil change. Knowing how and when to perform an oil change may not be difficult and does not take a lot of time. Essential for an oil change is the type of new oil you will use. The user mananual will often contain the specific type the manufacturer wants you to use, but this can be more expensive than even better alternatives. Knowing the available oil grades and those suitable for lawnmower engines will significantly help make the best and cost-effective choice. And when your lawnmower is aging, the type of oil will change as well.

What kind of oil do you use in a lawnmower:

There are two major types of engine oil for Lawnmowers: Synthetic oils and crude oil derivatives. The most commonly used oil type in lawnmowers is SAE-30. If the mower is used with a wide range of outside temperatures, a multigrade SAE 10W-30 will improve the cold start. Synthetic oils such as the synthetic variant of SAE 10W-30 or a Vanguard 15W-30 are suited for prolonged operating environments and other high-end engine applications. If you experience extremely cold temperatures, then SAE 5W-30 might aid your engine’s cold start.

This blog post will explain the differences in more detail and some useful techniques to perform an oil change yourself.

An overview of the Lawnmower Oil types:

Motor oils used for engine lubrication come in various grades. Each grade differs from the other based on viscosity at different temperatures. The motor oil is added separately in the engine crankcases. Only in 2-stroke engines, the oil is mixed with the gas.

● Recommended oil types:

Provided below are some of the most frequently used oil types. Each type performs its role at a specific temperature. Older engines generally have to use thicker oil. This helps against oil leaks.

– 1. SAE-30:

SAE-30 is the most commonly used motor oil for small engine types such as lawnmowers, chainsaws, snowblowers. SAE-30 means a viscosity rating of 30 as given by the Society of Automotive Engineers (SAE). The oil ratings range from 0 to 50. Highly viscous oils have a better ability to perform in warmer environments.  That is the reason you should prefer using SAE-30 motor oil if you’re living in a warmer climate.

– 2. SAE 10W-30:

SAE 10W-30 is a multigrade oil. Multigrade means that it offers a variable viscosity range. 10W means that the oil has a viscosity rating of 10 when the engine is cold (W means winter or cold start) and 30 when the engine is hot. The advantage of using SAE-30 is that it provides better performance when the weather is cold. However, using this oil grade may increase your oil consumption.

You can prefer using a multigrade oil if the temperature variations are significant in your region.

– 3. Synthetic SAE 10W-30:

The synthetic variant of SAE 10W-30 results in far better engine performance. Not only does it operate a variable temperature range and improve cold-weather starting, but it also decreases your oil consumption. You can use this grade of oil if you intend you maximize your engine’s service life.

– 4. SAE 5W-30:

Compared to 10W-30, SAE 5W-30 has a cold temperature viscosity rating of 5. This rating means that it is highly suitable for regions with the extremely cold environment. Since at low temperatures, any fluid’s viscosity increases, hence using 5W-30 instead of 10W-30 is a better decision if you happen to live in regions where the temperature drops below 0 degrees.

– 5. Vanguard 15W-30:

Vanguard 15W-30 is a synthetic oil that is best suited for small engine applications. It provides a relatively high cold-start viscosity. Hence, it is suitable for use in regions where the temperature stays moderate, such as coastal areas.

Since it is a synthetic grade, it is generally used for high-end engine applications such as commercial lawn mowing or pressure washing at service stations.

Note: Whenever you purchase the motor oil for your mower, please make sure that it reads “For Service SF, SG, SH, SJ” or higher.

How much oil does your lawnmower need:

Although your capacity’s exact specifications are best elaborated in the owner’s manual, we can indicate the oil capacity of different lawnmower types. So you have an idea how much oil you have to purchase.

● 1. Self-propelled mowers:

For walk-behind self-propelled lawnmowers, the engine’s oil capacity ranges from 15 oz to 18 oz.  For such engine types, it is recommended to perform the oil change after 50 hours of use. As a general rule, you should perform an oil change at the start of every mowing season to guarantee a smooth operation.

● 2. Riding lawnmowers:

Riding lawnmowers’ oil capacity is higher than that of self-propelled mowers since they are designed for a more prolonged and rigorous operation. Their oil capacity ranges from 48 oz to 64 oz. Please note that the engine must never be overfilled with oil. For this reason, always consult your owner’s manual. Such lawnmowers must perform an oil change after 100 hours of use. When replacing the oil, it is best to replace the oil filter as well.

Checking and changing the oil level:

You may come across situations when the oil change in your lawnmower becomes pretty imminent. If you want to perform the oil change by yourself, the instructions for doing that are provided below:

● Checking the oil level:

Checking the engine’s oil level is fairly easy and can be performed in a few steps.

– Step 1: Locate and remove the dipstick:

The oil dipstick helps you to check your oil level. It is generally present beside the engine and is fairly easy to find. Rotate the head of the dipstick clockwise and remove it gently. Clean any debris that lies on the dipstick cap.

– Step 2: Check the oil level on the dipstick:

The oil level is indicated by a couple of indicators at the bottom of the stick. If the oil level lies between these indicators, it is perfect, and you don’t need an oil change.

● Perform an oil change:

Occasionally, you might need to perform the oil change. It can be accomplished by going through the following steps:

– Step 1: Locate and remove the oil dipstick:

To start, you need to locate and remove the oil dipstick on your engine. If the oil color on the stick is black, the oil in your crankcase has become stale, and it calls for a change.

– Step 2: Dispose of the old oil:

For draining the old oil from your engine, the best method is to use an oil extraction kit available from an oil dealer at a low price. Insert the oil extractor’s hose into the oil hole and siphon the oil from the engine into the extractor kit’s tank utilizing a piston provided.

– Step 3: Addition of fresh oil:

After you have purchased the suitable oil type for your mower, perform its addition. It is better to use a funnel to ensure that the oil enters smoothly without causing any spills outside. Ensure regular checking of the oil level using the dipstick. Once the desired level is reached, close the dipstick and clear up the worksite.

Oil change for two-stroke engines:

The procedure described above is for four-stroke engines. You should consult the user’s manual that comes with your device to see if the engine is two-stroke or four-stroke. In general, you can know that your lawnmower is a two-stroke if it uses a gas and oil mix. If it uses just plain gas, it is a four-stroke engine. Although two-stroke engines are less prevalent due to emission regulations, there are still many on the market.

Two-stroke engines mix oil and gas. For that type of engine, you can not do an oil change. When you add the new gas mixture, there is new oil added as well. You can purchase the gas-oil mixture ready-made, or you can mix it yourself.

Related Questions:

1. Can I use 10W-30 instead of SAE-30 in my lawnmower?

Using SAE 10W-30 instead of SAE 30 is a very good idea. If you are not experiencing any cost-related constraints, you should switch to 10W-30 instead, as it provides a much better cold starting performance of your engine.

SAE-30 is single grade oil whose viscosity doesn’t change at hot or cold starting. 10W-30 has a cold starting viscosity value of 10. This rating makes it a highly preferred choice for use in winters when the engine is cold, and a low viscosity grade is needed for lubrication.

2. Can I use 5W-30 in a lawnmower?

5W-30 is a thin, cold-engine oil such as in snow blowers. If the weather in your region occasionally stays below zero degrees, you should switch to 5W-30 instead, as it provides better lubrication than thicker oils at low temperatures. However, if the temperature becomes high, the oil might become too thin to lubricate it properly. Hence, you should make a choice accordingly.

3. Should I use synthetic oils in my lawnmower?

Synthetic oils provide superior performance in regards to engine lubrication as compared to the crude oil derivatives. However, the use of synthetic oils does not affect the required oil change intervals. These oils are used where the engine’s prolonged operation is asked, and high durability is needed.

4. Is there any difference between lawnmower oil and car oil?

Generally, lawnmower engines take the same oil as used in automobiles. However, the owner’s manual for a lawnmower should be checked to see if the engine is sensitive to any additives or detergents. These small engines most commonly use SAE 30 or 10W-30.

Final Remarks:

You should remember that your lawnmower engine has various moving parts such as pistons and a crankshaft that operate at high velocities and higher temperatures. Hence, the continuous wear rate makes these components highly susceptible to overheat and fail, thus causing your engine to underperform and eventually seize. Therefore, the oil change should never be ignored, particularly at the start of the mowing season. Routine maintenance of the machine always ensures smooth and long-lasting performance.

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