Lawn mowers require oil, along with gasoline, to work properly. The lifetime of your lawn mower depends on what kind of oil for lawn mower you use.
Without oil, your lawn mower will just stop working. Chances are you will destroy your lawn mower forever if you forget to put oil into the engine.
It is that important! Luckily, oil is cheap and available at most stores. You may wonder what kind of oil you need to purchase.
Best Lawn Mower Oils for 2023
Lawn Mower Oil Buyers' Guide
Why Does Your Lawn Mower Need Oil?
The purpose of oil for your lawn mower engine, along with all other engines, is to lubricate the parts to keep everything moving.
Without oil, there will be too much friction caused by the moving parts in the engine. If you attempt to run an engine without oil, it will heat up so high that the metals can swell and stop working.
Oil is just as important for your lawn mower as it is for your vehicles!
How to Pick the Right Lawn Mower Oil Type
There are dozens of engine oils on the market. It can be hard to decide which type is perfect for your lawn mower’s engine.
The first thing you want to do is make sure it meets all standards set by the API – American Petroleum Institute. From there, you can make your decision.
- If you live in a region with varying temperatures, the oil rated at SAE 30W is typically recommended.
- If for some reasons, you need to mow the grass and it is below 32 degrees F, you will need to change the oil. SAE 10W 30 or SAE 5W 30 is a better choice. These are multi-viscosity oils that allow the engine to start in colder weather.
- If the temperatures go above 32 degrees, you don’t want to use a multi-viscosity oil because it will burn off quickly.
Synthetic vs. Conventional (Petroleum) Oil
All engine oils have one thing in common – they help to lubricate the engine. However, there are some differences between the two: synthetic and conventional oil.
The first thing you might notice is that synthetic oil tends to lubricate better because it is slipperier than other oils. Your engine will run better.
It also protects your engine throughout the widest temperature range. If you live in an area with fluctuating temperatures, synthetic could be a better choice.
Unfortunately, synthetic oil burns off faster because of its efficiency. Therefore, it might save you much more money than conventional oil.
Furthermore, synthetic oil is created from man-made materials. Such materials are harder to recycle after having used it.
Conventional oil is cheaper than synthetic, which is an appealing factor for many people. It is also friendly to the environment as it is a naturally occurring.
However, you can only use it during certain weather. If you only cut grass during one temperature range, it could be the better choice for you.
Also, those who have smaller lawns should stick to conventional oil.
What’s the difference between 2-stroke and 4-stroke oil?
2-stroke engine oils are designed to burn along with fuel, lubricating the engine and dispersing. 4-stroke engine oils are designed, as the name suggests, for 4-stroke engines, and do not burn off.
They circulate around the engine, lubricating all parts of the engine and dispersing heat. The two oils are compatible with their matching engine types (2-stroke and 4-stroke).
While both engine types use standard combustion to burn fuel and power your lawn mower, 2-stroke engines are lighter, and generally better suited for smaller lawn mowers in domestic settings. 4-stroke engines are heavier, but much more efficient, using a similar amount of petrol to complete double the revolutions.
Maintaining Your Lawn Mower Engine
Before you mow your lawn, you should check the level of motor oil each time. There is a gauge on the oil dipstick that allows you to determine the level.
Make sure you tighten the dipstick in the tube before you check the level! You want the level to be at the “full” line. It is important that you know how to maintain your lawn mower engine.
Small engines on lawn mowers require more regular oil changes. You should change the oil after every 25 hours operation for push mowers.
If you have a riding lawn mower or lawn tractor, you will need to change oil after every 50 hours of operation. You should change the oil filter, as well as the filter, whenever you change the oil!
If you didn’t use the lawn mower 25 hours this season, you should still change the engine oil after each season.
What to Look for in a Good Lawn Mower Oil
The manual for any lawn mower should have advice for the exact oil type to use with any given machine. If you’ve lost your manual, search online using the model number on the side or base of the machine.
Failing that, there should be a serial number on the engine that will give similar results. Synthetic oils are generally safer and can extend the life of your lawn mower, but do check to see if synthetic oils are suitable for your mower.
Often, it’s best to use a simple single-grade (SG) oil on older machines, but they will only work in hotter temperatures. Multigrade oil includes a mix of additives to support movement through the engine, while synthetic blends perform better at colder temperatures.
Picking Between Lawn Mower Oil Types
Picking between synthetic and conventional motor oil depends entirely on your preferences and location. The most potentially decisive factor is the weight you pick.
There are some types of oil that are multi-weight, such as the SAE 10W 30 listed above for colder temperatures. If you purchase a straight weight, that would look like the SAE 30.
When picking between multi-weight and straight weight, think about when you plan to use your lawn mower. If you only operate it during 40 degrees or warmer weather, you can go with a straight 30 weight. Your lawn mower will be perfectly fine!
On the other hand, if you use it during a wider variety of temperatures, a multi-weight would ensure your lawn mower works for years to come.
Choosing the Best Oil for Lawn Mowers
As above, the most important, and often overlooked consideration is between SAE 30 and SAE 10W-30 oils to ensure your mower oil is suitable for your local climate.
Hotter climates require SAE 30 oils, while cooler climates are typically better suited to SAE 10W-30 oils, which are less efficient, but more effective in those conditions.
If you’re not sure which to use, try SAE 5W-30, which works well in both settings. It’s not the most efficient but it can be a good safe bet for unsure gardeners.
Best type of lawn mower oil for push mowers
SAE 5W-30 is generally considered the best type of oil for push mowers. As well as working at all temperatures, with these relatively low-powered machines, it aids starting and can increase engine efficiency.
Best type of oil for ride-on and zero-turn mowers
While it is less efficient, SAE 10W-30 (non-synthetic oil) is good for larger machines in varying climates and will help to lubricate the engine in all conditions, as well as lubricating your engine.
It is also readily available for both 2-stroke and 4-stroke engines as standard.
Best lawn mower oil type for 2 stroke lawn mowers
In warmer parts of the US, go for an SAE 30 2-stroke motor oil. This standard formulation is pretty failsafe and will work in most parts of the country.
For cooler climates use synthetic SAE 5W-30 2-stroke motor oils which are slightly less efficient, but better suited to more challenging conditions.
Best type of lawn mower oil for 4-stroke lawn mowers
SAE 10W-30 4-stroke motor oil is ideal for any 4-stroke motor. The engines are generally well adapted to all weather conditions and work more efficiently anyway.
The cheaper, but slightly less-efficient oils are offset by the engine, and will generally balance out consumption against the more efficient gas use.
How to Change Lawn Mower Oil
The following is a guide only. Please refer to your operator’s manual if the guide below does not match with the build of your mower.
- Make sure the engine is off, and cooled (ideally, change the oil before use, not after).
- Place rags or newspaper beneath your work area, and loosen the plug with a socket wrench or pliers (depending on plug type). Then drain into a bucket or pan.
- Replace the drain plug and tighten it securely.
- If the lawnmower engine has an oil filter, check it and change it if necessary (once a year minimum).
- When removing the filter to check it, add clean engine oil to the filter gasket with a lightly oiled rag to lubricate the gasket.
- Replace and tighten the filter.
- Add mower oil up to maximum capacity (there will be an embossed line), then run the engine on idle checking for leaks.
- Turn off the engine.
- Secure the oil cap.
- Dispose of the old oil responsibly, either with curbside collections or local tips.
How Often to Change Lawn Mower Oil
You should change your lawn mower oil after roughly 50 hours of use. For a standard lawn, cut twice a week in summer, taking 30 minutes each time, which means once every 25 weeks (twice a year).
For larger lawn mowers, it’s worth checking the oil regularly, just as you would with a car, as it may need changing more regularly.
Lawn Mower Oil Frequently Asked Questions
Why does it matter what oil I put in my lawn mower?
Gas-powered lawn mowers have varying specifications, and using the wrong oil can cause overheating, and possibly fail to lubricate your engine entirely.
Standard motor oils are often too viscous, and will not lubricate at all, or burn off while using the wrong type can also lead to wastage, and needing to replace the oil too often.
Should I use 5W or 10W lawnmower oil?
5W oil works better at low temperatures, but both are generally interchangeable as they are both synthetic oils with low viscosity, and effective at lubricating most engine types.
How full should lawnmower oil be?
Lawn mower oil should always be filled up to the maximum line, or just below it. If you overfill, the engine can smoke, and while underfilling won’t damage your engine, it does mean more regular maintenance and refills.
Now You Know What Kind of Oil for Lawn Mower You Should Use
In the end, your engine would work using any oil, but it is better off that you spend time deciding the suitable kind of oil for your lawn mower lasting longer.
You can always take a look at the owner’s manual. It should have recommendations for what kind of oil for lawn mower you need to use.