SAE 30 Versus 10W-30: Which Oil Suits Your Lawnmower?

Oil is essential in any internal combustion engine, including lawnmowers. When choosing the right oil for your mower, the engine type and operating temperature play a significant role in determining what oil type suits your machine.

SAE 30 and 10W-30 are popular types of oils used in lawnmowers. But what are they? How do they compare? This article looks into SAE 30 versus 10W-30 to help determine which oil best suits your lawn mower.

The Key Takeaway

SAE 30 differs from 10W-30 in that it’s a single-grade (mono-grade) oil best suited for warm weather. It’s thicker than 10W-30, flowing a bit slower in colder climates. SAE 30 is more affordable than 10W-30 and effective in older lawnmowers. 

On the other hand, 10W-30 is known as a multi-grade oil because it works well in high and low temperatures. It’s thinner than SAE 30 and remains so even in cold temperatures. As a result, 10W-30 is ideal for winter use as it makes it easy to start the engine while keeping it lubricated. This oil is also best suited for newer mowers. However, the 10W-30 oil has a higher price tag than SAE 30. 

Since the temperature significantly impacts oil viscosity, it’s best to use motor oil suited for your machine and climate. If you want to be sure about the right oil type, check the manufacturer’s recommendation for your mower.

What Is SAE 30?

SAE 30 is a type of motor oil that works well with smaller engines. It’s a single-grade oil mainly used in machines operating at higher temperatures, usually above freezing. The “SAE” in this oil type is an acronym for the Society of Automotive Engineers (SAE).

This oil has one viscosity grade (30), thus the name single-grade oil. This rating in SAE 30 stands for oil viscosity when heated to a temperature of 212°F (100°C). According to the SAE, oil viscosity is rated from 0-60. That means SAE 30 has a medium viscosity, designed for warm weather.

Due to its thickness in viscosity, SAE 30 tends to retain its property at higher temperatures. If your mower engine heats up, the SAE 30 won’t experience a thermal breakdown. This oil offers sufficient engine lubrication in high temperatures and ensures long engine life.

What Is 10W-30?

10W-30 has viscosity ratings for hot and low temperatures, making it a multi-grade (double-grade) oil. It’s a perfect motor oil for lawnmowers in cold and warm climates. Like SAE 30, 10W-30 has a 30-viscosity rating for hot temperatures.

This means it can retain its property even if the mower engine heats up. It will lubricate the engine and prevent it from overheating, which might cause severe damage.

The “10W” in 10W-30 oil is a viscosity grade for cold temperatures. The “W” stands for winter. This means the oil’s viscosity at low temperatures (0°F/-18°C) is rated at 10. If you’re using this oil at extreme temperatures, it will remain viscous to lubricate the engine parts.

Motor oils that don’t have winter ratings can get thick in colder climates and lead to starting and lubrication problems.

How Do They Compare?

When comparing SAE 30 versus 10W-30, most people wonder whether the two have similarities. The truth is, both work well in smaller engines such as lawnmowers. They also come from the same brand. If you live in warmer climates, both oils will work well in your mower without experiencing a thermal breakdown.

However, several differences set these two motor oils apart. Let’s explore the SAE30 vs 10W 30 differences in detail to help you choose one that works well for your situation.


The main factor that sets SAE 30 and SAE 10W-30 oils apart are their viscosity differences. If you place the two motor oils upside down, you’ll notice their flow rate differs based on the temperature. The two have different viscosities (thickness) at different temperatures.

SAE 30 is thicker than 10W-30 and performs well in high temperatures. It can retain its property (surface film) despite working in warm climates. However, SAE 30’s thickness doesn’t suit lawnmowers operating in colder climates. It tends to shrink too much in low temperatures and operates with poor pumping ability.

Conversely, 10W-30 is a good choice for lawnmowers operating in low and high temperatures. It has a similar viscosity rating at high temperatures, like in SAE 30.

Additionally, 10W-30 oil has a 10W viscosity rating at low temperatures. The oil won’t become thick when temperatures are low, thus keeping your engine lubricated. 10W-30 is thinner and might lose its viscosity in high temperatures.

Oil Grade

SAE lists every oil type with a numerical code to show its grade number. This code is essential in helping you know how each oil performs in different temperatures. Motor oil can be single-grade or multi-grade. When comparing SAE 30 versus 10W-30, you can differentiate them with their grade numbers.

SAE 30 has one numerical code, thus a single-grade or monograde oil. 10W-30 has two numerical codes, thus a multi-grade or double-grade oil. Your engine will warm the oil at low temperatures and guarantee better pumping and fuel economy.


The oil performance in your lawn mower can vary depending on the density of oil used. SAE 30 weighs 0.869 g/cm³ (869 kg/m³) at 30°C (86°F) and standard air pressure. This oil tends to lose its density in low temperatures.

10W-30 weighs 0.865 g/cm³ (865 kg/m³) at °15.5°C (60°F) and standard air pressure. While 10W-30 performs well in warm weather, it can lose density when temperatures get too hot. 

Performance in Different Temperatures

Both SAE 30 and 10W-30 work great in a warmer climate (at an operating temperature of 100°C) and retain their viscosity. However, it’s good to note that 10W-30 might lose its viscosity when the engine heats up. 

While SAE 30 works well at an operating temperature of 100°C (212°F), it can experience a thermal breakdown in higher temperatures. For example, it can break down when the engine overheats and reaches 121.1-126.7°C (250-260°F). When this happens, you’ll need to wait for the oil to cool down before resuming your work. 

When it comes to performance in low temperatures, SAE 30 does not do well. You’re likely to notice the engine failing to start or having lubrication issues. This oil is ideal for spring, summer, and early fall applications.

10W-30 is a good option for individuals looking for motor oil that can retain its thickness at different temperatures. The 10W viscosity rating means it can perform well in low temperatures (-18°C/0°F) without compromising its consistency. You can rely on this oil to start your mower’s engine and keep it lubricated on chilly days. 

Oil Additives

Additives can be a blessing or a curse in your mower’s engine. On the brighter side, oil additives can enhance engine performance and allow it to perform well in different temperatures. 

When comparing the additives in SAE 30 and 10W-30 engine oils, both contain three to five percent of additives. 10W-30 has higher additives that allow the oil to retain its thickness in different temperatures. 

These additives allow the oil to work well in lessening rust, wear, breakdown and emissions. Additives in engine oil can also help trap dirt to keep the engine sludge-free. In other words, oil additives offer consistent protection while allowing long engine life. 

Some landscapers may not settle for 10W-30 due to its many additives. Oil additives that are in excess are known to deteriorate oil’s performance. Too many additives in engine oil can cause the following:

  • Promote more foaming 
  • Work against friction
  • Reduce fuel economy
  • Damage to the catalytic converters

Remember to change the oil filter regularly if you’re using 10W-30 in your mower. You can do this when changing the oil. Changing the oil filter allows you to eliminate additives buildup that could cause problems in your lawn mower. 

Unlike 10W-30, SAE 30 has fewer additives. You can use this oil on warm days without worrying about the damage that results from excessive additives. However, this oil may not offer the best protection when it comes to rust, wear, and breakdown, unlike 10W-30. 


While both SAE 30 and 10W-30 engine oils work well in smaller engines, such as lawnmowers, they may not be effective in all machines. SAE 30 oil is best suited for simpler and more predictable engines, such as old lawnmowers. 

On the contrary, 10W-30 is ideal for newer model engines that require motor oil with higher viscosity at a lower temperature. This oil retains its proper viscosity when operating in colder and warmer climates. 


Both SAE 30 and SAE 10W-30 have reasonable prices, although the 10W-30 has a higher price tag. SAE 30 can be your go-to oil for your lawn mower if you live in a warmer climate and wish to save some money. This engine oil will offer protection against erosion while being eco-friendly. 

SAE 10W-30 is slightly expensive but can offer high protection to the engine despite temperature extremes. You’re assured of eco-friendly engine oil thanks to its reduced emissions. 

SAE 30 Versus 10W-30: Pros and Cons

Pros of SAE 30

  • Can withstand high temperatures
  • It’s affordable
  • Good for small motors (lawnmowers)

Cons of SAE 30

  • Not ideal for use in a colder climate, such as in winter
  • Not effective for large engines

Pros of 10W-30

  • Can withstand freezing temperatures
  • Slightly less expensive
  • Works well in larger motors

Cons of 10W-30

  • Not as optimal in higher temperatures
  • Less effective for older lawnmowers

Is It Safe to Use SAE 30 Instead of SAE 10W-30? 

You can sometimes use SAE 30 oil instead of SAE 10W-30 and vice versa. While using single-grade oil instead double-grade oil might cause problems in your mower, there are times you can get away with it. For example, if your area experiences temperature fluctuations, you can use SAE 30 oil instead of 10W-30 when the weather gets warmer. 

The moderately warm weather won’t affect the oil’s viscosity or cause problems when starting. You’ll, however, want to test how SAE 30 flows by placing it upside down. If it behaves as it does in warm weather, you’re okay to use it. 

Similarly, you can use SAE 10W-30 oil instead of SAE 30 in hot temperatures without problems. The two engine oils have the same viscosity rating at high temperatures, making it safe to use one instead of the other. 

You can also use SAE 30 oil instead of SAE 10W-30 if the mower’s manufacturer recommends it. In most cases, you’re okay to use SAE 30 in older mowers instead of 10W-30. Always double-check your mower’s manual to avoid using the wrong oil type.

Can SAE 30 Be Mixed With 10W-30? 

You can mix SAE 30 and SAE 10W-30 and use the blend in your mower. However, combining the 10W-30 and SAE 30 is advised against because the two have different viscosity levels for low temperatures and density. 

While it’s true that this blend might work in your mower, it may eventually leave the machine in bad condition. So you’re better off using one over the other as long as it’s ideal for the mower.

Consider their viscosity and density to understand why these two oils may not create an effective blend. 10W-30 retains its thickness in cold weather, while SAE 30 does not. Additionally, 10W-30 is a thinner and heavier-weight oil, while SAE 30 is thicker and lighter-weight. 

These differences can reduce the chances of creating a perfect blend of the two oils. As a result, using this blend in your lawn mower is not advisable as it may cause problems with your machine. 


Are you still wondering which oil best suits your lawn mower? Several factors, such as operating temperature, engine type, and price, will largely dictate which oil you choose. Hopefully, this SAE 30 versus 10W-30 comparison article helps you determine which works well for your machine.

SAE 30 is a single-grade and lighter-weight oil best suited for warmer climates. It’s also thick and retains its viscosity when operating in hot temperatures. This oil is affordable and ideal for older lawnmowers.

On the other hand, 10W-30 is a multi-grade and heavier-weight oil that works well in warmer and colder climates. It offers consistent protection to your engine, thanks to its additives. 10W-30 is slightly less expensive and works well with newer-model lawnmowers.