What is The Type of Oil For Lawn Mowers?


We tend to forget about the oil that is in our mower! This results in building up sludge and carbon on bearings and other parts for all dirt and contaminant. And this will wear down your engine.

The internal combustion lawnmower engine of gas-powered one runs on by burning the gasoline as a fuel. And you need the best type of oil for lawnmowers to lubricate the pistons and other moving parts. The oil lessens the friction between the moving metal parts and ensures longevity.

You don’t neglect the oil change of your car, so why for your mower? It is also not a small investment!

What Are The Types of Oil For Lawn Mowers?

When you take your mower out of the garage after its winter break, it might seem dull. That could indicate that you have to change your 4 stroke lawn mower oil.

Before changing your small lawnmower engine’s oil, it is crucial to understand the oil type and capacity. The equipment you use, outdoor temperature, and the engine’s size – all of these influence the mower oil type and costing.

Firstly, if you want to know how to change oil in a push mower, you must know the oil capacity.

However, lawnmower engines come in two basic configurations – 1) two-stroke engine 2) four-stroke engine. Let’s check out the engine types below.

Four-Stroke Lawn Mower Oil

The four-cycle engines are the standard type for riding or push mowers. Here, the piston needs to go through two complete cycles at each revolution of the engine. The circle consists of drawing into the engine cylinder of the air-fuel mixture, compressing the fuel-air mixture, ignition of the mix by the spark plug, and so on.

However, this type of engine needs a reservoir for engine oil to lubricate the connecting rods and other engine parts.

The expensive lawnmower with a four-stroke engine comes with oil-level dipstick and oil filters.

The four-stroke engines produce more torque even at a low rpm. So, this type ensures durability, fuel efficiency, and lower emissions. So, to avoid any damage, you have to use the best oil brand for lawnmower (Check below).

Two-Stroke Lawn Mower Oil

In this type, just one back-and-forth movement of the piston ensures complete combustion cycle, compression, ignition, and exhaustion. You need to mix the motor oil right in with the gasoline as there is no oil crankcase to fill or maintain.

This type of engine has more power than a four-stroke and lighter. However, the two-stroke engine burns a small amount of oil with each ignition revolution, and so manufacturers are now eager to have four-stroke engines. Generally, the brands that manufacture two-cycle mowers also sell oil for their particular mowers.

Again, there are mainly two types of oil for mowers – motor oil and small engine oil. The largest producer of outdoor tools – Briggs and Stratton, once had done a survey and found that people have a misconception about automotive oil and small engine oil.

You have to remember that the small engine runs hotter than automotive engines. The former one is designed for high-temperature environments and can protect the engine from getting overheated.

Since 2-cycle engines do not come with a dedicated lubricant source like 4-cycle engines, these engines have a high tendency to wear out quicker than the latter one. So, you need to mix high-quality two-stroke oils to reduce the wear significantly.

Let’s see the Recommended Different Oil Types and What Oil can Work Best at Certain Temperatures – 

  • SAE 30: Suitable for warmer temperatures and most common oil for small engines.
  • SAE 10W-30: Varies on the temperature range. Though this grade of oil improves cold-weather starting, it may increase oil consumption.
  • Synthetic SAE 5W-30: It delivers the best protection at all temperatures and improves starting with less oil consumption.
  • SAE 5W-30: Suitable for freezing temperatures.
  • Vanguard 15W-50: Great for continuous-use, such as commercial lawn cutting or pressure washing.

Synthetic oil is always a better choice

The synthetic oil ensures better viscosity, wear and deposit control, and low-temperature fluidity. Regular use of synthetic oil extends your machine’s service life. However, the synthetic one comes with a higher price tag than the conventional one.

The Lawn Care Equipment For Changing The Oil

  • Catch pan for oil
  • Socket wrench
  • Fresh sae 30 motor oil
  • Oil filter
  • Spark plugs
  • Oil filter wrench
  • Old newspaper or cardboard
  • Funnel
  • Air filter
  • Fuel preservative

How to Check and Change the Oil in Your Lawn Mower?

You need to change your oil regularly, and the best rule of thumb is to examine the quality of the oil on the dipstick often. You need to change the oil when the appearance turns black and soiled.

If you are riding new lawn mowers, you need to change the oil early (generally after five hours of use). 

The steps are following –

Checking the Oil Level

It would be best to check the engine’s oil level before starting the lawnmower and before each use.

While checking it after use, make sure to let the engine cool down completely to avoid any mishap.

You have to make sure your machine is on level ground; otherwise, you will get a false reading.

Check the Dipstick

Take the dipstick out and wipe it with a clean rag. Then, insert it back in and check its reading. Oil level should be between the full and add marks.

You can do this a second time to confirm the reading. And allow adequate time for the oil to settle before rechecking the oil level.

Again, the dipstick is for checking the oil level and how clean or dirty the oil is. After checking, you may find any of the below results –

  • If the oil level is acceptable and the oil appears clean and dark amber, your engine oil is fine. So, you can go ahead and mow the lawn.
  • If the oil seems clean, but you get a low reading, add oil before mowing.
  • If the oil appears dirty, it’s time to change the oil. You can mow the lawn first before doing this maintenance. The warm oil will drain out of the lawnmower much easily. You need to add a small amount of oil to the crankcase before mowing if the motor oil level is low. And then change the oil after you finish.

Preparing the Mower

If you want to change the old oil, start up the mower and let it warm up for about 1 minute. This process will warm up the oil slightly and make it drain out more easily.

Always disconnect the spark plug wire to prevent accidental starting. Wipe around the oil fill and drain plug area to avoid dirt and debris falling into the crankcase.

 Draining the Oil

  • Tilt the deck with the air filter or spark plug side up.
  • Keep some newspaper and an oil pan or jug below the mower.
  • Take a 3/8″ drive socket wrench and extension (no socket) to turn the plug counterclockwise to permit the old oil to drain.
  • If the plug also allows like a fill cap, it may have two prongs. So, use your hand to loosen it or use a screwdriver or hex key for additional torque.
  • Remove the drain plug by twisting clockwise and tightening with a box wrench or adjustable wrench. You can skip this step if your engine does not have an oil filter.

Replace the Oil Filter

You might need to change the oil less frequently of the lawnmower, which comes with an oil filter, as the filter will catch large particles of dirt and debris. But you need to change the filter at least once each year or whenever the manufacturer recommends it.

Replace it by twisting the cartridge counterclockwise until it screws loose. You can do this by hand or with a filter wrench. Then, carefully clean the metal rim where the oil filter seals against the engine.

Then, put the new filter onto the machine and tighten it by hand until the rubber seal slightly compresses against the filter mount’s metal rim. You can push the filter slightly more using a filter wrench.

Refilling the Engine Oil

Remove the plug on the mower. Insert a funnel into the fill opening, and slowly pour fresh motor oil into the engine crankcase. The capacity for –

Walk-Behind or Push Mowers: 

  • 15oz or 18oz [maximum].
  • It is recommended to change engine oil every 50 hours or annually

Riding Mowers:

  • 48oz or 64 oz [maximum].
  • It is recommended to change engine oil every 100 hours or annually.

You can use a dipstick to check the oil level. You can also check out this video.

Make sure to clean the filler stick clean before each check.

Now, screw the filler plug back into the fill opening when the crankcase is full, and wipe up any oil that is spilled anywhere. Put the spark plug wire back again.

Now you are ready to mow. Do it regularly to keep a lawnmower operating efficiently for many years.

Some Facts And Tips You Should Know –

  • Do not go for special additives.
  • Some recommendations of high-quality detergent oil – ‘For service SF, SG, SH, SJ’ or higher
  • For all temperature range, you can use synthetic oil.
  • Generally, every 25 to 50 hours of lawn care, you need to change oil for the lawn mower’s longevity.
  • The riding mower needs motor oil that has high viscosity.
  • The mixture of gas and two-stroke oil for two-cycle engines depends on the machine like the ratio can be 32:1 or 50:1.
  • Air-cooled engines consume about an ounce or around 30 ml of oil per cylinder, per hour.
  • Do not overfill the mark.
  • The fuel has to contain a maximum of 10% ethanol or gasohol, and a higher amount than this is not acceptable.
  • Before using the mixed gas in a two-stroke engine, give the can a shake to get properly mixed.
  • If you want to extend the life of your lawnmower’s oil, try using a high-quality fuel stabilizer treatment. It will prevent varnish and gum buildup in your mower.

Frequently Asked Questions (FAQs):

Can I put car oil in my craftsman lawnmower?

Though the lawnmower engines are smaller than car engines, they work using the same combustion principles. So, the same type of oil can go with both types of engines. But the lawnmower engines might need different viscosity. That's why the conventional oil bottle for mowers comes with a numerical value which denotes the thickness, like best SAE 30 oil for lawn mower or 30-weight by SAE oil.

Can you use regular motor oil in a lawnmower?

The regular motor oil might clog or disable some units completely. But the straight 30W or multi-grade oil like 10W-30 will be fine. And if you are dwelling in a cold area, the 5W-30 motor oil will be fine too. So, you only need to make sure the oil comes with good quality with an SF, SG, SH, or SJ rating.

What kind of oil for the transmission in a gravely zero-turn mower?

The best oil for zero-turn mowers, according to gravely, is the 20w-50 or 15w-50 synthetic oil.

What happens if you don't change oil in lawn mower?

If you don't change the oil or use the wrong oil or the oil level gets low, you will end up with an overheated engine that tends to shut down quickly. And this will lead to damage to the engine compartments which its warranty won't cover. So, it is recommended to change the oil after 25 hours of use in case of push mowers and 50 hours of service in case of ride-on mowers.

Conclusion

In Mediterranean-type climates, you have to make the lawnmower maintenance a continual project. The draining and replacing of oil is crucial because the oil carries away the ash and carbon happened by the combustion in the engine’s high-temperature whirl.

As all engines don’t use the same oil, you have to check the operator’s manual to figure out the type of oil for lawnmowers. After the right decision, your machine can contribute to many years of hassle-free mowing. So, you will not get one-size-fits-all doubts.

Happy mowing!

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