Can You Use Car Oil in Lawn Mowers?

Can You Use Car Oil in Lawn Mowers Image

Oil is a must-have component for both car and mower engines to operate as designed, but can you use car oil in lawn mowers? Absolutely yes!

Mower engines are smaller than car engines, yet, they still function with the same combustion principles.

That means they need engine oil to fulfill different purposes like protecting the engine from deposit buildup.

In fact, if you use car oil in a lawn mower, it’s a great way to extend the life of your engine. But there are a few things you should keep in mind when you use car oil in a lawn mower.

Keep reading to learn more!

Can You Use Car Oil in Lawn Mowers?

Yes, you can use car oil in lawn mowers but avoid making it a frequent routine. That’s because mower engines use different oil viscosity than some car engines. So by feeding your mower engine with the incorrect oil grade, your engine will likely suffer damage.

Therefore, you need to refer to the owner’s manual for the correct engine oil of your mower to avoid such risks.

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

Both lawn mower oil and car oil have essential elements that provide maximum lubrication to engines and minimize the buildup of harmful carbon deposits.

They also have additives that reduce harmful emissions and smoking. But is there a difference between lawn mower oil and car oil?

Yes, there is a big difference when you use car oil and lawn mower oil. First, lawn mower engine oil or small engine oil has a thicker consistency than car oil.

That means if you use car oil of low quality in a lawn mower engine, it won’t work as expected because the oil will run off too quickly to lubricate well.

Secondly, the recommended oils for lawn mowers are single grades such as SAE 40 or SAE 30 in hot conditions or SAE 10W30 in cold conditions.

By contrast, cars use multi-grade engine oil conducive to multitasking in both hot and cold temperatures.

What Kind of Oil Goes In a Lawn Mower?

The type of oil used in lawn mowers depends on your local climate, your mower size, and if you will use your lawn mower commercially.

It’s wise to choose the right type of oil in a lawn mower, compatible with your local temperature for your mower to work more effectively.

Here is a list displaying lawn mower oil types and their conducive conditions.

  • SAE 30 – warmer temperatures, common for small lawn mower engines.
  • SAE 10W30 Synthetic Oil this option tolerates all temperatures but may increase oil consumption.
  • Synthetic SAE 5W-30 – This synthetic oil works efficiently in all temperatures and has low oil consumption.
  • SAE 5W-30 Synthetic Oil- cold temperatures.
  • Vanguard 15W-50 Synthetic Oil – varying temperature range.

Related: Top John Deere hy gard equivalent


Choose high-quality lawn mower oil types classified as SF, SG, SH, SJ, or higher when buying a lawn mower oil because such options are fortified with essential elements to boost your engine’s performance.

Can I Use 10W30 Car Oil in My Lawn Mower?

Can You Use Car Oil in Lawn Mowers Image

Yes, you can use 10W30 car oil in your lawn mower, but you need to factor in various aspects such as temperature and the engines’ condition.

For instance, 10W30 car oil in a lawn works best in air cooled engines, specifically for modern lawn mower engines in cold and warm climates. Older lawn mower engines may benefit from SAE30 car oil.

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

Yes, 5W30 motor oil works well with lawn mowers as it has the same flow rate as mower engine oil at average operating temps.

5W-30, which is an advanced full synthetic oil, also gives your engine proper lubrication in a wide range of temperatures to maintain velocity.

The motor oil is designed to keep your engine running like new by providing exceptional wear protection, cleaning power, and overall performance. 

Can I Put 10W40 in My Lawn Mower?

No, 10W40 is a detergent oil, so if you put it in your lawn mower, it will foam and fail to lubricate your lawn mower as expected.

This type of oil also has a thick consistency meaning it’s too thick to pass through the smaller oil passages in a lawn mower.

How to Check the Oil Level in Your Lawn Mower

It’s essential to have the right amount of oil in your lawn mower to lubricate all moving parts.

This enhances your lawn mower’s efficiency and minimizes the chances of your mower suffering internal damages.

That said, you need to be well-versed in checking the oil level in your lawn mower to avoid running it with insufficient Oil.

Note: the method you use to determine the oil level in the lawn mower depends on whether you have a dipstick or not.

Read along, and consult owner’s manual for your lawn mower to find out how to check the mower’s oil level.

Step 1: Park the Lawn Mower

First, place your lawn mower in an open level area and shut it off, and allow it to cool. Wait for about 10 minutes for the lawn mower to cool as checking the oil with air cooled engines will produce the most accurate reading.

Step 2: Locate the Fill Cap

Next, locate the oil fill cap. It’s usually found on the crankcase, but its position varies depending on the lawn mower brand.

Step 3: Clean the Oil fill Cap and the Crankcase

After locating the oil fill cap, follow with cleaning the exterior area of the crankcase around the lid.

Please avoid skipping this step because removing the cap without cleaning it means dirt and debris will plunge into the crankcase and contaminate the Oil.

Also, note that the buildup of debris in the crankcase can congest the oil lines leading to a decrease in lubrication for the moving components.

So the best approach to cleaning this area is to wet the end of a clean cloth with water, then clean the cap area.

After cleaning the oil fill cap area, remove the cap by applying pressure and twisting it counterclockwise. You should see the dipstick attached to the inner face of the oil fill cap.

Step 4:  Inspect the Oil Level

After exposing the dipstick, wipe it clean with a damp cloth so the reading will be accurate.

After that, confirm that the teeth on the oil fill cap match the dipstick tube’s grooves, then twist it clockwise to reinstall it.

Let the dipstick settle inside for a moment, then remove it again and check the oil level towards the low end of your dipstick blade.

The oil line should be between the full and add marks. If the oil level is not enough, add new Oil and recheck the level.

Reminder: Avoid adding too much Oil in one pour; a few ounces at a time is enough to avoid overfilling.


  • Check the oil level after each pour but allow the Oil to settle first before rechecking.
  • Be sure to clean the dipstick after each pour to get precise results.
  • If you don’t get the correct measurements, wipe the dipstick again and recheck the oil level.
  • Don’t add too much oil. The optimum oil level should be between the minimum and maximum levels.

Step 5: Reinstall the Oil Fill Cap

After confirming that Oil is at the recommended level, reinstall the fill cap turning it clockwise until it’s tightened. After that, your lawn mower should be ready to use.

Please normalize checking for the oil level in your lawn mower before mowing. This way, you will get updated on the oil level, and the lawn mower won’t run out of oil.

Can You Use Car Oil in Lawn Mowers Image

Checking the Oil Level Without a Dipstick

Please follow these steps if your lawn mower doesn’t come with a dipstick. First, place your lawn mower on a leveled surface, shut it off and let it cool.

After that, locate the oil fill cap and clean the area around it before removing the lid. You do this to prevent any impurities from falling into the Oil and contaminating it.

Next, remove the cap and check for the slot marked inside the fill hole. The oil level should be close to this slot or above it.

Suppose the oil level is too low; add fresh Oil until the level emerges to the slot. Then reinstall the cap by turning it clockwise with minimal pressure until it’s tightened.

What If I Put Too Much Oil in My Lawn Mower?

When your lawn mower engine has little oil, bad things can occur: friction increases between moving parts, the engine gets hot, and worst of all, all moving parts seize when they get starved for lubrication.

Bad things can also materialize when you feed your lawn mower engine too much oil. For instance, too much oil can result in foaming, which your oil into a bubbly fluid with air pockets that weaken the lubricating and cooling properties.

Therefore, the oil pump finds it hard to distribute the engine oil around, so some moving components won’t get sufficient Oil to run as expected. These increases wear and tear, resulting in a damaged machine.

Too much Oil also increases the oil pressure, putting extra stress on gaskets and seals that keep your Oil from leaking out of the engine.

This added stress triggers wear on the seals and gaskets, which can be a costly repair with time.

So if you have overfilled your engine oil, you need to master how to remove the excess oil so your lawn mower engine does not suffer premature damage. Check out these steps below:

First, wipe the area around the crankcase with a damp rag. This prevents dirt and other unwanted substances from falling into the Oil.

Next, tilt your lawn mower on its side to avoid exposing the carburetor and the combustion chamber to the Oil.

If oil leaks into these parts, it will be challenging to start your engine. After cleaning the crankcase, unscrew the oil tube and drain out the lubricant.

Alternatively, you can use an oil extractor pump to do the trick. Just insert a tube inside the engine oil fill hole, then pump out the Oil into a safe container.

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

Dirt from combustion and intake can contaminate your lawn mower oil and degrade its lubrication properties.

If that happens, your lawn mower oil will begin executing its functions less effectively, hence changing lawn mower oil brings back the mower to its efficient capacity.

But what happens if you don’t change the oil in your lawn mower? Failing to change lawn mower oil results in increased wear within the engine’s components.

This can lead to permanent damage when the lawn mower engine seizes. So considering that potential harm, how soon should you replace your lawn mower oil?

You need to change lawn mower oil after 25 to 50 hours of use. That’s because no oil can last for more than a year, considering its functional properties will have been exhausted.

Ideally, changing lawn mower oil prevents harmful dirt and stubborn debris from inflicting any significant damage to your engine.

How Long Can a Lawn Mower Run Without Oil?

A lawn mower can run for around 30 minutes without Oil before bursting into a cloud of smoke.

It’s hazardous to operate your lawn mower without oil as the engine components will rub against each other, causing premature wear.

Why Is My Lawn Mower Oil Darker When Changing it?

When you pour new Oil into the crankcase, it’s usually in a golden color. But with time, dirt particles, heat, and agitated air decrease the Oil’s consistency, quality, and color, resulting in a dark soot buildup.

However, this dark color doesn’t necessarily mean anything strange as Oil can be black and still be effective.

What Is the Difference Between 10W30 and 10W40 Oil?

Both 10W30 and 10W40 oils are common for their ability to reduce wear to the metal components of your engine.

But what’s the difference between these two? The main difference between 10W30 and 10W40 lies in their viscosity and temperature fluctuation.

10W40 Oil is thicker than 10W30 at high temperatures. That means 10W40 automotive oil is suitable for those living in hot areas because it’s designed to protect your engine from enduring wear in the extremes.

This Oil is also designed for engines that get hotter faster as it flows freely and still maintains enough viscosity for your engine.

On the other hand, 10W30 Oil is an economical solution and works best in cold climates. That’s because it only deals with the engine heat and not extra stress from the environment.

Besides, this Oil also reduces engine temperatures when it heats up during winter. You can also use it in hot regions, but be sure it will thin out when temperatures rise and fail to lubricate the internal parts well.

So to be safe, use 10W40 for improved protection at high temperatures.

How Often Should You Change Oil in a Lawn Mower?

When it comes to maintaining your lawn mower, the essential aspect to focus on is the frequency of oil changes.

This is because motor oil offers several benefits like minimizing friction, cooling the engine, and preventing rust or corrosion.

When the motor oil in your mower gets dirty, unwanted contaminants can build up, causing engine wear. That’s why it is crucial to have a maintenance schedule to change your motor oil regularly.

So how often should you change the motor oil in your lawn mower? You should change your lawn mower oil after 25 to 50 hours of use.

This way, your investment will last for years to come. But if you have a new lawn mower engine, change the motor oil after the first five hours of use.

This is because a new lawn mower can leave metal filings in the Oil. So if you allow them to sit in the Oil for a while, your engine will suffer excessive wear and tear.


How often you change lawn mower oil depends on a few aspects, which I will discuss below:

The first aspect is how often you mow your lawn. If you’re in an excessive growing season, you will have to change the oil regularly because of extended hours of use per week.

Another consideration is your lawn’s condition. You will need frequent changes if you have rough terrain with lots of debris and small obstructions, unlike a flat lawn.

How to Change the Engine Oil In Your Lawn Mower?

Changing oil in your lawn mower is essential as it guarantees the smooth running of the engine.

This project is very straightforward and can save you from hiring a serviceman to do it for you. Please sift through the steps below to learn how to replace oil in your lawn mower.

Step 1

First, you will need to prepare for the oil change. Start by moving your mower to a leveled surface, then let the engine run for 10 minutes.

You warm up the engine to enable the oil flow to be more freely and get all the stubborn dirt out of your engine.

After that, use a damp rag or an air compressor to clean the oil fill area. Then place a pan on the side of the mower, which you will tip to drain out the Oil.

Step 2

After finishing the prep work above, your lawn mower should be ready to have its used Oil oozed. Next, remove the oil fill cap from its position and tilt the mower on its side to drain out the Oil.

Ensure the carburetor faces up to avoid Oil from entering it. If not, your carburetor will not function normally, and the engine will have difficulty starting.

Leave the mower to rest on its side for at least one minute, so all of the existing Oil drips out.

Step 3

This step involves changing the oil filter. You will want to place a safe container below the oil filter as you unscrew it because a bit of oil will ooze out of the filter.

You then take a screwdriver and loosen the oil filter. Once the old Oil drains out entirely, remove the old oil filter and prepare the new one.

Step 4

You can now install the new oil filter. Before that, use your fingertips to apply a small coat of Oil to the outer lips of your new filter.

This ensures that the new filter seals tightly when you install it. After that, tighten the new oil filter into place until it reaches the plate it seals against.

Once you’re through, you can now refill your lawn mower with new Oil. However, remember that overfilling Oil is as dangerous as underfilling it.

So be sure to confer with the owner’s manual to know the right amount of oil your mower consumes. Once you’re set, take your new oil and fill your lawn mower with oil.

You will want to stop several times in the process to check the new oil level with a dipstick. This reduces the chances of overfilling.

If you reach the required oil level, replace the oil fill cap as your oil change is now complete.

How Often Should You Change a Lawn Mower Spark Plug?

A spark plug offers an ignition source for lawn mowers. It incorporates a firing electrode, a center electrode, and a threaded shank for its attachment into the engine block.

If your lawn mower spark plug goes bad, mowing will be tough. So how often should you change your lawn mower spark plug?

You should change your lawn mower spark after every 25 hours of rough handling. This ensures that your engine ignites without difficulty.

Can You Leave Oil in a Lawn Mower Over Winter?

Yes, you can leave Oil to stay in your lawn mower over winter but be sure it’s fresh Oil. I say this because old oil in a lawn integrates moisture, gasoline, soot, and acids that can corrode the engine’s internal parts over the winter.

So before winter, ensure you change the oil and run it for a few seconds to feed all the internal components with clean Oil.

Here are other things to do when preparing your lawn mower for winter.

1. Remove the battery

Unplug your mower battery during the winter period and clean its terminal with a battery cleaner product.

You will also need to coat the terminals with a terminal protector for added protection. The essence of removing the batteries is that they might lose charge quickly in cold conditions.

2. Clean your mower

As you prepare to store your mower over winter, brush off grass, leaves, and mud from your mower.

You can use a stick to scrape off any stubborn dirt, but remember to disengage the spark plug before cleaning or doing other mower maintenance.

3. Add Fuel Stabilizer

Fuel stabilizer helps prevent your engine’s fuel system from clogging and your mower not working the following growing season. Even better, this medium excludes the need to drain fuel before storage.

So after adding a fuel stabilizer to your oil tank, run the mower for a couple of minutes for the stabilized fuel to circulate throughout the engine’s fuel system.


Always store your mower with a full tank of fuel to avoid moisture from condensing in the oil tank, which can create rust and clog the carburetor.

How Do You Know If Your Spark Plug is Bad in Your Lawn Mower?

It’s easy to tell if you have a defective spark plug by paying close attention to the following signs:

Hard Start

You can tell that you have a faulty spark plug if the engine takes time to start. In small riding mowers, you will notice that it takes more pulls on the starter rope before the engine ignites.

You will also realize the mower fails to start when you turn the key on bigger mowers. This happens because the spark created by the spark plug is too weak to ignite the mixture in the cylinder.

If you are experiencing difficulties to start your mower, you can still use a car to jump start your lown mower.

Poor Performance

Another indication of a faulty spark plug is poor engine performance. The engine may die out when mowing. Besides, a defective spark plug may also cause misfires with the engine popping.

Physical Appearance

Disconnecting the spark plug and assessing its appearance can help you determine if it’s time for replacement or not.

Check to ensure the centre electrode has a flat top. If it’s rounded, you will want to replace the spark plug.

Also, examine any cracks or chips in the porcelain sheath. Please replace the spark plug if you notice any damage.

Sometimes the spark plug may be in good condition, but it is surrounded by wet gasoline or other residues. This won’t need replacement.

Instead, clean the spark plug with a wire brush and adjust the gap between the electrodes for the spark plug to resume working.

Other signs include too much fuel consumption and gas running out quicker than usual.

What Makes Lawn Mower Spark Plugs Go Bad?

Spark plugs go bad because the electrodes wear down with time, making them shorter until they are not long enough to get the engine running.

Also, the buildup of carbon around the spark plug can make it less effective and fail to ignite the engine.

So with the above dangers in mind, you need to protect your spark plug’s structural integrity for it to function as designed.

You can achieve that by regularly replacing your spark plugs after the duration recommended by the manufacturer.

Here’s How to Change Lawn Mower’s Engine Oil


Do lawn mowers take regular gas?

Yes, lawnmowers take regular gas, but the fuel must be fresh and clean octane gasoline with a minimum of 87 octane rating and, at most, 10 per cent ethanol.

Final Thoughts

Lawn mowers rely on oil to neutralize the friction created from the moving parts. The Oil ensures that your mower continues working efficiently, extends the lifespan, and you will have to deal with fewer repair costs.

But have you asked yourself what if the mower engine oil is depleted? Can You Use Car Oil in Lawn Mowers?

Yes, it’s practical to use car oil in a lawn mower, but ensure the quality you use is compatible with your mower engine. This is because some mower engines are sensitive to the additives in car oil, so using the wrong grade oil can reverse the effects of lubrication.

Leave a Comment