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

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.

Understanding the Concept of the Codes

The “W” in the 5w20 and 5w30 oils types stands for “winter.” The number before W which is 5 in these cases represents the rating of the viscosity of the oil in cold weather temperature or conditions of coldness.

The number which comes after W, such as 20 or 30 in these cases, stands for the weight of the particular type of the oil when it warms up inside the engine of a vehicle.

To analyze the difference between 5w20 and 5w30 oil using the codes, varying weather conditions would come into play. When in winter, for example, the type of oil viscosity that would be advisable to choose would be one which is thin.

With this, the lubrication of the parts of the engine would be smoother unlike when the oil has a higher viscosity. Likewise, when the temperature is higher or at least average, the viscosity of the oil chosen would be one which is higher. So the lubrication would flow in line with the high-temperature rate.

5w oils are multi-weighted. This is unlike the 5-only oils which are single weighted. The difference is that the multi-weight oils will be thicker and useful at normal temperatures than the single weighted oils.

The single weight oils would be thin and as such, protection of the engine of your vehicle would be a little lesser.

A man changing the oil of a car

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.

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.

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.

A man pouring oil unto the car

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.

Frequently Asked Questions (FAQs)

1. 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.

2. 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.

3. Why Are Cars Designed With Engines Supporting Different Oil Weights?

The cars are designed to serve different purposes and to be used in different environments. The various engines supporting different oil weight make them suitable for different situations.

4. Is It Applicable to Interchange Between 5w20 and 5w30?

No. If your manufacturer has recommended one type of oil, you should stick with it. This is because engines are designed to run on specific types of oil which comes with different viscosity.

5. What Is the Difference Between Single and Multi-Grade Oil?

Single grade oil is a pure type of oil that cannot be modified. It has no additives while the multi-grade oil has additives thus not pure.

A rack full of engine oils


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.

Leave a Comment