Can You Use Car Oil in a Lawn Mower? (YES and NO!)

Has the time come to change your lawn mower oil? If so, you might be wondering if you can use motor oil in a lawn mower. Some people will tell you that you don’t have to buy separate oil for your car and your lawn mower. This is true to some extent, assuming that you use high-quality oil in your car.

Keep reading to find out more about the type of oil to use in your lawn mower. We’ll also answer some questions you might have about lawn mower oil and offer some tips for changing the oil.

So, let’s get right to it!

What Oil Can You Use In a Lawn Mower?

The type of oil you use will make all the difference in how long your lawn mower lasts and the quality of service it gives you. There are many types of oils out there but we recommend that you only invest in a high-quality oil. If you want to learn more about lawn mower oil, we recommend this interesting tutorial.

One of the factors to keep in mind when picking lawn mower oil is the climate in your area. But, you should also heed your manufacturer’s recommendation for the best oil to use in your mower.

Some of the oil options from which to choose are:

  • SAE 30: This is the most common type of oil used in small engines like those found in lawn mowers.
  • SAE 10W-30: This high viscosity oil is specially formulated for cold temperature. It is ideal if you live in cooler regions but colder temperatures may mean higher oil consumption.
  • SAE 5W-30: If you live in very cold temperatures, you will need specially made oil that can withstand extreme weather. The SAE 5W-30 is a good choice.
  • Synthetic SAE 5W-30: Synthetic lawn mower oil is the preferred oil for lawn mowers. Not only is it gentler on the metal parts of the mower; it also offers protection regardless of the temperature. You will get the most out of synthetic oil whether you live in extremely low or high temperatures. Most synthetic SAE 5W-30 oils are also formulated for lower oil consumption.

Does Lawn Mower Oil Need Additives?

Does Lawn Mower Oil Need Additives

When changing oil for your lawn mower, it is best not to use special additives. You will come across claims encouraging you to add special concoctions to ‘improve your lawn oil.’’ But, these are unnecessary; they may adulterate and lower the quality of the oil.

That said, some manufacturers recommend using oils with additives such as detergent additives, anti-wear agents, friction modifiers, viscosity index improvers, or dispersants. Each type of additive plays its own role whether that is lubrication or separating solid particles from the oil. Before using any additive, be sure to find out what your manufacturer recommends for your particular type of lawn mower.

Is Car Oil the Same As Lawn Mower Oil?

Carmakers urge their customers to use premium conventional oil, which includes synthetic 5W-30, 5W-20, or 5W-30 oil for cooler temperatures. For areas with slightly higher temperatures, 10W-30 oil is advised.

Oil for four-stroke lawn mower 

Modern lawn mowers have a four-cycle or four-stroke engine, which stores oil and gasoline in separate compartments, as is the case with motor vehicles. Most lawn mower engines use SAE30 oil or 10W-30 oil, which are also popular options for auto engine oil.

The oil you use for your car’s engine is the same one you can use for your lawn mower. However, make sure that your motor oil is of high quality before using it in a lawn mower engine, which is comparably smaller and less hardy. The quickest way to shorten the life of your lawn mower is to use low-quality engine oil.

Oil for two-stroke lawn mower 

Two-stroke lawn mowers are no longer common and have been replaced by the more fuel-efficient, cleaner, and quieter four-stroke mower. But, just in case you have a two-stroke mower, you should not fill it up with the same oil that you use in a vehicle.

Unlike four-stroke engines that have separate compartments for gasoline and oil, two-stroke engines mix gasoline with oil. A lightweight oil is required to mix with the gasoline to thoroughly lubricate the parts of the small, lightweight engine.

For this reason, you should not use motor oil in a two-stroke lawn mower, as the oil tends to be heavier and can bog down the small engine. Instead, use your manufacturer-recommended lightweight oil to protect your engine and preserve its longevity.

How Often  Should You Change Lawn Mower Oil?

How Often  Should You Change Lawn Mower Oil

Every lawn mower maker will recommend their own timeline for changing the engine oil. Generally, for walk-behind lawn mowers, it is best to have an oil change after every 50 hours once a year.

Owners of riding mowers are advised to change the oil every 100 hours or so, or whichever comes first. If your lawn mower or its engine is new, it is best to add new oil after five hours of operation.

That said, these are just general guidelines. You might have to change your oil more frequently than this depending on factors such as high temperatures, mowing uneven terrain, or too much dust. All these tough conditions can quickly dirty your oil and necessitate regular oil change.

Tips For Changing The Oil In Your Lawn Mower

Now, you have found out that you can use motor oil in a lawn mower as long as the oil is of high quality and has not been disqualified by the lawn mower manufacturer. Next, let’s take a look at some things to keep in mind when changing lawn mower oil.

1. Inspect the dipstick

A sure way to know whether it is time for an oil change is to check the dipstick. If the level is lower than the add marks, that is a good sign that your mower needs fresh oil. Ideally, the oil level should be between the add and full marks.

To check engine oil, unscrew the dipstick cap and pull it. Wipe the dipstick with a clean rag to check the reading then replace the readings. Take the cap out again and view the oil level.

If the oil level is lower than the add mark, pour fresh oil gradually and be sure not to fill the compartment with excessive oil. Recheck the oil level to ensure that it is enough. Check your oil regularly to ensure that there is always enough in the mower.

2. Run the engine to make the oil less viscous

You will need to remove the old oil before filling up the mower with new oil. But, first, run the engine to warm the oil and make it more fluid for ease of draining. Five minutes of the engine running is enough to make the oil less viscous without getting it too hot and potentially dangerous.

Something important you should do is to detach the spark plug lead and spark plug from the engine. This will prevent the engine from accidentally starting.  

3. Empty the oil

There are several ways to drain the oil from the lawn mower. You can do it through the drain plug, dipstick plug, or using an oil extractor kit.

If you decide to use the drain plug, you will first have to tilt the mower to its side. Be sure to turn off the fuel tap to prevent oil from trickling into the engine and potentially causing a fire.

Check with your dealer or manufacturer which method to use to empty the oil through the drain plug. Some manufacturers recommend tilting the mower on its side where the breather is to prevent oil from getting to the air filter or carburetor. Others advise that you lay down the mower on its handle and hold it in place with a rock or other heavy item.

Alternatively, you can use an oil extractor kit to empty the oil tank. Simply insert the oil extractor’s tube into the tank through the oil fill plug and siphon the old oil out. This method is faster and a lot less messy.

4. Pour in the new oil

Add the new oil through the fill plug. A neat trick is to use a funnel to avoid spilling oil as you pour it into the small inlet. Then, replace the dipstick and check that the oil is at the correct level. If you are satisfied with the oil level, tighten the dipstick cap into place and reconnect the spark plug wire.

Summary

Your lawn mower needs clean, high-quality oil to function properly and to serve you for longer. As we’ve explained, you can use motor oil in a lawn mower as long as it is a good quality oil and is the appropriate type of oil for your specific mower.

Generally, SAE30 is a good choice for both cars and lawn mowers but you should always check with your manufacturer or dealer if you aren’t sure which oil is best for your machine. When the time comes to change your oil, keep in mind the tips we have outlined above and your lawn mower will thank you with many years of service.

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