What is Lawn Mower Oil? Definition, Types & FAQs
Lawn mower oil typically functions in the same way as other types of small engine oils, which is by lubricating and cooling the parts of the machine while they work at high speeds and volatile temperatures. A lawn mower engine may not be the biggest motor, but the power of a blade mechanism is quite substantial – and bigger riding mowers use extremely large motors indeed.
As providers of a wide range of lawn mowers and other garden machinery, with great prices and hassle-free aftercare, we are well-placed to explain what lawn mower oil is and other details. You can browse our fuels, oils and lubricants or contact us if you have any product questions.
What Types of Lawn Mower Oil Are There?
The kind of oil a lawn mower needs will mainly depend on manufacturer recommendations, but there are a few different types of small engine oils that are most commonly used:
- Fully-synthetic lawn mower oil: This is a special type of oil that is artificially made in a laboratory or factory setting, which will provide high performance for engines.
- Semi-synthetic lawn mower oil: A mix of synthetic oil but with special additives, which are included to add performance benefits – such as preventing it from freezing.
- Multi-grade level lawn mower oil: A type of oil that has a wide viscosity range, due to the use of additives, which makes it very versatile and useful for many types of engine.
- Single-grade lawn mower oil: Single-grade oil is suitable for lawn mowers, and other pieces of heavy machinery, that have very high-temperature requirements.
These are the broad categories of lawn mower oil, but the key is finding the oil with the right viscosity for your mower’s operating engine temperature. Most oils have a viscosity rating that has been given to them by SAE International (previously the Society of Automotive Engineers).
What Oil is Best for Lawn Mowers?
The viscosity rating relates to the thickness of the oil, which essentially determines how well it will flow in the engine. Common types of lawn mower oil grades include the following:
- SAE 30, which is used for smaller engines with air-cooling features
- SAE 10W-30, which is a version of the above that also works in cold temperatures
- SAE 5W-30, another variation of SAE 30 but designed for even colder environments
If you have a 4-stroke engine, it is usually safe to choose SAE 30 oil, provided conditions are not too cold, but it is always worth checking manufacturers recommendations. Older push mowers may use 2-stroke engines, so you might need to mix motor oils to get the right viscosity.
What Happens When You Do Not Use Lawn Mower Oil?
If you do not use the right type of lawn mower oil, or you neglect to top it up regularly, you will risk damaging the engine. Too thick oil can stuff up the engine parts and oil with too little viscosity causes issues like leaks, which can be potentially dangerous in a lawn mower engine.
You should check the oil level regularly if you are to keep the mower’s engine in the best condition, which will extend the lifespan and performance quality of all sorts of mowers, other outdoor power equipment and garden machinery.
How a Lawn Mower Engine’s Power Cycle Works
It can help to understand some of the intricacies of an engine’s power cycle, which is essentially what makes it run. Most lawn mowers have the following phases and use 4-stroke engines:
- Intake stroke, where the fuel is sucked into one side of the engine
- Compression stroke, where the file is squashed up at the top of the engine
- Ignition stroke, where the compressed fuel is ignited by using a spark plug
- Exhaust stroke, where combusted fuel fumes exit the other side of the engine
The parts of the engine are rapidly moving and require a very steady level of lubrication to work effectively. Any ‘sticking’ with too thick oil will reduce the power cycle’s efficiency and can easily damage the engine over time.
How to Know When You Need an Oil Change
You do not need to check the oil constantly, but every 10 or 20 hours of use it is worth checking if the levels have dipped or at least estimate how much is left before a top is needed. If a mower is new it is worth changing the oil after less than 10 hours – but always check the user manual first.
Using your lawn mower in certain conditions can also increase the frequency of needing an oil change. Conditions that will increase your engine’s oil needs include the following:
- Using the mower in excessive mud, dust and dirt
- Mowing over wet grass, as well as mosses and other absorbent vegetation
- Mowing across large areas of grass, which will put greater strain on the machine
- Using the mower in very hot conditions, which puts more demand on an engine
The oil capacity of each engine can vary, but keeping it at a healthy level by regularly checking the dipstick on the oil tank will make sure it does not get too low. Most lawn mowers can have around 35-40 hours of operation without an oil change, but this can vary so it is worth a check!
Lawn Mower Oil Explained
There are synthetic and other commercial varieties of lawn mower oils we describe above. If you choose the wrong type of oil you risk damaging the engine. Most mowers use 4-stroke engines, which will work with SAE 30-grade motor oil, but you always check the recommendations.
We hope that you understand a little bit more about what lawn mower oil is, how it works and what goes into selecting the right type. Always check with a manufacturer if there is any doubt. When you buy a lawn mower from us we can help find the right oil and provide quality aftercare.
Take a look at our fuels, oils and lubricants or get in touch with us if you have any questions.
