What Is the Difference Between 5w20 and 5w30 Oil? Expert Answer

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5w20 and 5w30 oils are types of oil which have differences in their rate of viscosity. The rate of viscosity of a liquid describes its thickness and stickiness and, therefore, talks about the property of that liquid to flow easily.

When the number is higher (an example of this here is the number 30), then the oil will have more viscosity, and so, have more property of thickness and heaviness and a little ability to flow.

When the number is lesser (an example of this here is the number 20), then the oil will have a lesser viscosity than the one with the higher number, and therefore, have a lesser property of thickness and heaviness and more aptitude to flow.

Oils are essential for vehicles and are the reason to be conscious of these codes and numbers.

Even in such cases when you give your cars to mechanics to change the oil for you, you will do well if you know about the properties of these oil types.

After all, oils are the lifeblood for the engine of your vehicle.

In drawing the difference between 5w20 and 5w30 oil, an example to employ is water. You would notice that water flows very smoothly, and so water will be said to have a viscosity which is very low.

This will help you in understanding this concept. Consequently, the concept of viscosity in the types of oils is critical in determining the long-lasting of your engine and your vehicle.

5w20 vs 5w30 Oil: Head to Head Comparison

Now, when it comes to picking up your engine oil, you will have to choose one depending on the season or temperature simply. This means you will use a different oil in winter than what you will use in summer.

A man changing the oil of a car

Cold Temperatures

In cold temperatures, 5w20 oil will be the better choice to go for with its thin nature and its ability to bring about less friction due to its viscosity level.

The 5w20 oil type will flow more smoothly than the 5w30 oil. This ability to flow easily confers on it the best choice in cold temperatures. It is because there will be minor heat and the thin nature will still accommodate the oil to flow in-between engine parts and cause lesser friction.

5w30 oil, on the other hand, is thicker and will flow lower than the 5w20 oil. This makes it unideal for cold temperature. Although it has the same rating of 5 in regards to winter, the oil nevertheless weights 30.

So, when there is no much heat, the higher weight rating would not be functional and may hurt the car’s engine. However, you may consider engine block heaters to maximize the oil.

Hot Temperature

In a climate which is hot, the 5w30 oil type would be appropriate for use. This oil type would not break down easily and take longer to break down due to the combination of chemicals that it is composed of.

5w30 oil will form much resistance to heat, and so, when there is much heat, it will last longer in engines and not break down easily.

5w20 oil, meanwhile, would not be appropriate for hotter temperature. This is because this oil tends to break down quickly and has a low viscosity which makes it thinner.

It cannot withstand much heat, and it will quickly create friction between two engine parts. This type of oil would undergo heating up more rapidly than the 5w30 oil and may result of a possible oil leak.A man pouring oil unto the car

How Will You Choose the Appropriate Oil Type?

To know which oil type to choose, you should consider two things:

  • The temperature level of your environment
  • The description in the manual of your car for your car’s engine

Although, it might be sometimes safe to use the 5w30 engine oil type as this will generally be useful for your vehicle when you face a problem in deciding which to use.

However, the best is to know the appropriate type of oil to choose according to the two criteria given, since engines may have varying properties. This way, you will be protecting the life of the engine of your vehicle.

When you check the manual of your car, you would be provided with the type of engine oil to choose. Many a time, each vehicle is specifically built to use a particular type of engine oil.

This would extensively go to say that it is good to know the specific type of oil to use as using one which is against the manual description can hamper the long-lasting of your vehicle.

At other times, you would be good to take into consideration the temperature and climate of your surroundings. In colder temperatures, the best type of oil to go for is the 5w20 oil type because of its thin nature and low viscosity.

In hotter temperatures, however, the best oil type is the 5w30 oil which breaks down less easily and has a higher viscosity. So, you can use the criteria given above to determine the best type of oil for your vehicle.

A rack full of engine oils

Frequently Asked Questions (FAQs)

Why Should I Use the Right Oil and Not Just Any?

For longer engine life, less non-routine maintenance and for better mileage, it is required that you use the right oil designed for your engine.

Between 5w20 and 5w30 Which One Is Economy Friendly?

Many experts recommend 5w20 to 5w30 when it comes to economy friendliness. It causes less friction in the engine as it is very thin.


The two types of oil, 5w20, and 5w30 have been a point of discussion for so long. Many people have been found themselves confused to choose 5w20 vs 5w30 two types of oil. Have you been among them?

This article has laid down the differences to make your choice stress-free and straightforward.