SAE 30 vs 5W30 – Differences + Which to Use in your Lawn Mower

Oil is an important addition to the engine; it cleans, lubricates and protects the system moving parts. SAE 30 and 5W30 are popular motor oils with the same viscosity rating of 30 when hot. So, what is the difference between SAE 30 and 5W30?

SAE 30 and 5W30 have different viscosity ratings when cold which brings differences in their uses. SAE 30 is single-grade oil that is suitable for small engines. On the other hand, 5W30 is a multi-grade oil that can handle very cold conditions thus suitable for complex heavy engines.

SAE 30 vs 5W30 – What’s the Difference?

Here is a summary of the main differences between SAE 30 and 5W30:

SAE 30 Engine Oil5W30 Engine Oil
A single-grade oil that is suitable for small engines.A multi-grade oil, suitable for complex engines.
It flows well only in warm and hot temperatures.It flows well in both cold and hot temperatures.

SAE 30 differs from 5W30 in terms of operation, viscosity, operating temperature, composition and pressure. Let’s have a deeper look at each of them:


SAE 30 is ideal for small air-cooled engines such as those in lawnmowers, small-sized tractors and snow blowers. However, it is rarely used in modern advanced engines. Modern vehicle engines require oil that is flexible for both cold and hot temperatures.

With 5W30, it is a multi-grade oil that is suitable for advanced engines in buses, SUVs, vans and trucks. It is suitable for engines that use light-duty petrol and diesel. It is effective in lubricating, sealing and protecting internal engine components from various weather conditions.


Viscosity is a measure of how well the oil pours at a certain temperature. In some cases, it is referred to as weight. A low rating means the oil is thinner while a higher rating means thicker oil. SAE 30 oil has a viscosity rating of 30. This means it flows well in warm or hot temperatures.

On the other hand, 5W30 also has a viscosity rate of 30. However, in cold temperatures, the 5W30 oil becomes 5-weight thinner. This feature makes it easy to operate in cold weather conditions more efficiently than SAE 30 motor oil.

Operating Temperature

SAE 30 motor oil is recommended for temperatures above 40 degrees Fahrenheit (4 degrees Celsius). The engine may experience a hard start when using SAE 30 in cold temperatures. However, it reaches its viscosity peak at 212 degrees Fahrenheit (100 degrees Celsius).

It breaks down when the engine temperature is around 250 to 260 degrees Fahrenheit (121 to 127 degree Celsius). At this point, the engine will start to overheat.

On the other hand, 5W30 is optimal in hot engines up to 212 degrees Fahrenheit which is the same as SAE 30. However, it is tolerant to cold temperatures below 40 degrees Fahrenheit (4.44 degrees Celsius) due to its thinness. Therefore, it’s ideal for cold winter temperatures.


Many motor oil contains detergents with additives to trap dirt and keep the engine free from sludge between changes. However, some people prefer oil without this additive as they believe it does more harm to the engine than good. However, SAE 30 does not contain these additives.

5W30 is available as pure motor oil as well as synthetic conventional which contains some additives. These synthetic additives tend to improve engine performance and lifespan. However, you should be able to change the oil together with the filter to prevent clogging from the buildup of dirt and additives.

Oil Pressure

5W30 is thinner than SAE 30. This means that it creates less pressure in comparison to SAE 30 and hence giving the engine a longer life. On the other hand, SAE 30 can withstand a considerable amount of pressure. Can withstand high pressure from extreme temperatures of up to 212 degrees Fahrenheit.

Can I use 5W30 instead of SAE 30 in my Lawn Mower?

Yes, you can use 5W30 instead of SAE 30 in your lawn mower because they share the same viscosity grade 30. SAE 5W30 is a multi-grade engine oil with a viscosity of grade 5 for low temperatures and a viscosity grade of 30 for high temperatures.

5W30 is ideal for different temperature conditions due to its multi-grade features. It protects the engine both in high and low temperatures. It is an ideal choice for lawnmowers in areas that receive cold winter weather conditions.

5W30 oil can be used to run both single and multi-viscosity appliances such as lawnmowers, powerboats, snow blowers, tractors, buses, SUVs and trucks. However, you cannot use SAE 30 in place of 5W30 because of its single viscosity.

Using car oil in a lawn mower may be fine, but the opposite cannot work. Using SAE 30 instead of 5W30 in a heavy engine causes several problems such as jammed operations, especially in cold temperatures.

SAE 30 or 5W30 – Which is Better?

To identify which is better between SAE 30 and 5W30, let’s have a deeper look at each of them.

SAE 30 Engine Oil

SAE simply means Society of Automotive Engineers. It is an international organization of individual engineers with a mandate of providing different grades of automobile products such as engine oil among others. It also provides recommendations on how to use the product.

Engine oils are graded depending on their viscosity. According to the Society of Automotive Engineers, engine oil viscosity is rated on a scale of 0 to 60. Low-graded engine oil tends to be thinner than high-graded oil.

Therefore, SAE 30 is a single-grade oil with a viscosity rating of 30. Single-grade oil can also be rated as a warm-grade oil or a cold-grade oil. In this case, SAE 30 is a warm-grade oil, which means that it performs best in warm temperatures. It has an optimum performance at 100 degrees Celsius.

SAE 30 oil is suitable for small engines such as lawnmowers, small tractors, snow blowers and chainsaws among others. It is also a non-detergent oil best for use in air compressors and a hydraulic system where oil additives are not required.

SAE is also used in old vehicle engines and some 4-stroke engines such as motorcycles and powerboats. However, it is recommended to read the manufacturer’s instructions before using this product in your engine. It should be compatible with your engine.

5W30 Engine Oil

5W30 is a multi-grade oil containing some additives to improve performance and prolong engine life. Using this product has numerous benefits for your engine. Here are some of them:

  • Contain detergent additives that clear dust and other debris from the engine.
  • It lubricates different engine components to reduce friction and improve efficiency.
  • Reduces wear and tear on engine components to prolong their lifespan.
  • Helps to cool down the engine and hence preventing it from overheating in high temperatures
  • Helps the engine to function efficiently in low temperatures.

SAE 5W30 is a multi-grade oil with a viscosity of 5 in low temperatures and 30 in high temperatures. It is ideal for use in both warm and cool climate regions that experience cold winter seasons. It is suitable for use in vehicles with advanced engines.

Also Read: Can I Use 10W30 in a Lawn Mower instead of SAE 30?

Final Thoughts

Now that you know the differences between SAE 30 and SAE 5W30, you can make the best decision when choosing one for your engine. SAE 30 is a single-grade oil suitable for small engines while 5W30 is a multi-grade oil best for different vehicles and trucks.

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