Difference between 5w30 and 5w20 | 8 Basic Comparisons

difference between 5w30 and 5w20

Engine oils are the core fluid of a car. It helps the vehicle to perform well by maintaining the engine’s life. However, if you already have a car or cars just fascinate you, you probably have seen something like 5w-30, 5w-20, or other similar codes mentioned on the engine’s cap. Before we jump into what these numbers and the letter W placed between represents, let’s sneak into a specific term called Viscosity

When we point at fluid’s thickness (whether the fluid is thicker or thinner), we basically indicate the fluid’s viscosity level. The more viscous the liquid, the higher the level of viscosity. Precisely saying, Viscosity is a measurement of fluid’s resistance to flow.

The codes mentioned above are two common oil types that display viscosity ratings. The first part of the numbers includes the letter W, which stands for winter. The first number (5w) that includes a W shows the viscosity rating when it is working in a colder temperature and the second number (30/20) shows the viscosity when it is hot. That means the oil will behave like SAE (Society of Automotive engineers) 5 grade when it’s cold, and the oils will act like SAE 30/20 grade when the temperature is warmer. 

Because there are two different numbers joined together, these types of oil are called multigrade oil. Multigrade engine oils can be used in a wide range of temperatures. 

It helps to keep up with the engine by maintaining the friction between the moving parts and resisting the machine from breakdown.

So, as per core concepts, the oil that behaves like 5 SAE grade in colder temperature and 30 SAE grade in a hot climate is known as 5W30 engine oil. On the other hand, the oil that behaves like 5 SAE grade in colder temperature and 20 SAE grade in a hot climate is defined as 5W20 engine oil. 

So, the difference between 5w30 and 5w20 is in the level of their viscosity and how they behave in various conditions. Still, there is a lot to dig into; you need more information to choose the right one for your car engine.

Comparison chart

Difference5W-30 Oil5W-20 Oil
DefinitionA multigrade oil with 5 winter rating and 30 warmer ratingA multigrade oil with 5 winter rating and 20 warmer rating
ThicknessThickerWinter rating= 5
Hot rating = 20
Viscosity ratingWinter rating = 5
Hot rating= 30
Performs better in colder climates compared to 5w30
Performance in colder climatesPerforms less efficiently in colder climates compared to 5w20Performance less efficiently in a warmer climate than 5w30
Performance in warmer climatesPerforms better in warmer climates than 5w20It gives a higher mileage during colder conditions.
MileageIt gives higher mileage during hot conditions.The engine works efficiently during colder climates.
Engine performanceThe engine works efficiently during hot climates.It lubricates optimally and creates less friction during cold climates.
Lubrication and frictionIt lubricates optimally and creates less friction during hot climates.Costs less than kitten foods

What is 5w30 oil?

5w30 is a semi-synthetic or conventional oil type that works better in hot temperatures because it has a higher viscosity rating. In order to ensure the operating temperature, multigrade oil like 5w30 goes through various tests before it gets certified. The cold viscosity rating includes tests that range from -10 to -40 degrees Celcius. And the hot viscosity rating includes tests that range from 100-150 degrees celsius. 

This oil is specifically formulated to handle excess heat and friction in car engines at a higher temperature. As for its thickness, 5w30 needs more time to get thinner as the oil heats up. Therefore, compared to 5w20, 5w30 is preferred for engines or climates that are more likely to heat up faster. 

On the other hand, in comparative colder conditions, 5w30 is less recommended as it tends to freeze quickly compared to 5w20. The engine may also experience hiccups or late start issues because it will take more time to distribute the oil to the engine’s moving parts.

However, when the operating temperature is in a normal condition, as for the higher thickness level, the 5w30 motor oil works better than the 5w20 by keeping up with the lubrication system. It helps the engine to circulate faster by reducing the friction and lubricating the surface between the cylinder and piston. When it comes to mileage, the 5w30 performs better with a high mileage car in warmer climates.

What is 5w20 oil?

5w20 is a partially synthetic or conventional multigrade oil type suggested to use in colder climates. The number 20 after 5w refers to how it behaves in hot temperatures. 5w20 has higher pumpability in colder climates because it has lower viscosity in hot climates. Like 5w30, the 5w20 multigrade oil is tested at similar temperatures to get certified. 

One of the core properties of engine oil is that its viscosity starts to decrease as the oil heats up. For that reason, the engine parts move slower if the oil gets thicker. So, the lower the winter viscosity is, the fewer chances to take time to increase the density. 

Take the example of a liquid that has a higher viscosity, such as honey, as it’s thicker and heavier, and it becomes comparatively tough for you to move your finger beneath the surface. But in a thinner fluid like the water, you can move your finger significantly easier. The same happens with the engine’s moving parts. And if the engine parts cannot get the right environment to move in their required rhythm, they are more likely to break down. 

When the viscosity in hot temperature is lower in 5w20 oil, this type of oil will get thinner in less time as it heats up than other engine oils that have higher hot viscosity. But at a lower temperature, 5w20 will take less time to get thicker as for the lower density. As a result, the engine will get more time to operate at an optimal level. For that reason, engine oil like 5w20 is recommended in colder climates. The 5w20 motor oil works well with a high mileage car in colder weather.

The key differences between 5w30 and 5w20

  1. 5w30 is a type of multigrade car engine oil that has a 5 winter rating and 30 warmer ratings. On the other hand, 5w20 is a type of multigrade car engine oil that has a 5 winter rating and 20 warmer ratings. 
  2. 5w30 engine oil has a higher viscosity rating in warmer conditions. So the thickness of 5w20 is less compared to 5w30.  
  3. 5w30 is preferable in warmer climates. Conversely, 5w20 is preferable in colder climates. 
  4. As the engine heats up, the 5w30 takes more time to get thinner in a hotter condition than 5w20. 
  5. As the engine heats up, the 5w20 takes more time to freeze in a colder environment than 5w30. 
  6. 5w30 breaks down quickly in colder weather than the 5w20. On the other hand, The 5w20 breaks down quickly compared to 5w30 in a hotter climate.
  7. 5w30 creates less friction and deals better with friction in hotter conditions than the 5w20 oil engine. Resultantly, the engine performs better. 
  8. 5w20 handles the engine and friction better during colder conditions. As a result, it gives a higher performance by increasing the engine’s efficiency than 5w30.

5w30 vs 5w20: which is better?

The car manufacturers recommend specific oil types based on various car engines. As for several personal recommendations of car mechanics, sometimes people use 5w30 in a car engine that recommends 5w20 or the other way round. 

You need to understand this, and if a car manufacturer suggests a specific motor oil type for a particular engine, it has definitely been recommended because that specific oil type worked better during testing. 

When it comes to 5w30 and 5w20, the two types of oils give enhanced efficiency according to the environment. So when it comes to comparison, the 5w30 oil performs better in hot climates than the 5w20. And in cold climates, 5w20 is definitely a better choice. Not to mention, 5w20 is definitely a better choice for fuel economy than 5w30.

Frequently asked questions (FAQs):

What happens if you put the wrong oil in your car?

The viscosity level recommended for specific oil engine types is crucial. If manufacturers suggest you use a specific type of engine oil, that means they have tested that particular oil against the car engine. If you use the wrong oil in your car, it may increase the risk of hampering the car engine and decrease the performance. It can also permanently damage your car motor.

Can you switch from 5w30 to 5w20?

5w30 and 5w20 are two of the most widely used types of motor oils. As for the availability, many car users use them interchangeably. However, if your car manufacturers recommend you to use a specific type but are using the other, you should definitely switch to the proper kind according to the recommendations.

5w20 vs. 5w30 which is best for ford?

If you are in colder condition, it is better to use 5w20 to get a good performance and a better mileage. But if you are in a climate that has a higher temperature, 5w30 can be a better choice than 5w20 for your car engine.


The difference between 5w30 and 5w20 is in their level of thickness. The 5w30 is thicker compared to the 5w20. The thicker the oil is, the higher level of viscosity it has. Therefore, an oil that comes with higher viscosity is a better choice for engines in warmer conditions. On the other hand, the oil that is thinner works better in colder conditions.

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