Can I Use 5w30 Instead Of 5w20 & Vice Versa? [Debunked]

Wondering if you should use 5w30 instead of 5w20 while changing engine oil? We understand the issue. Because they are made by the same manufacturer and have identical names.

So, can I use 5w30 instead of 5w20?

In theory, yes but practically you shouldn’t. They have the same winter oil rating. But the 5w20 has a lower viscosity than the 5w30. The 5w30 will show more resistance to fluidity resulting in lower efficiency. However, in warmer climates, the 5w30 will protect your engine better. Whereas, in colder climates, it’s better to keep using the 5w20 oil.

However, that was just a brief discussion. You should know more before making a decision.

So, let’s jump straight into the article!

5w30 Vs 5w20: Overall Comparison

5w30 and 5w20 are two Multi-grade oils. The viscosity rating of them differs. This is the result of oil showing individuality in different temperatures. One rating is for winter and another one for warmer temperatures. 

The first number with ‘W’ as initial, means winter rating. In this case, 5 is the rating and it’s the same for both. This shows the similarity between them in colder conditions. However, at operating temperature (100°C) 5w30 becomes thicker than 5w20.

Now, you understand whether to interchange them or not. But they can be really similar, yet different. 

So, it’s better to learn the non-identical properties between them in an elaborated way. Because not knowing the detailed differences can be fatal for your engine. Here, we have summarized the differences between them –

Output HorsepowerLowerHigher
Fuel EconomyLowerHigher
Engine Protection SuperiorInferior

So, you have an overview of the differences between them. Let’s check the thorough analysis-


Viscosity is the measure of a fluid’s resistance to flowing. It portrays the moving fluid’s internal friction. Higher the viscosity, more hindrance to the flow.

Oil rating mentions the viscosity of it. If oil has a higher rating that means it has a higher viscosity. Meaning it flows less smoothly. So, between 5w20 and 5w30, the latter one has a higher viscosity.

Low viscosity oil is normally preferred in cold weather. Because the flow of oil becomes much smoother. As a result, this elevates the engine’s performance.

On the other hand, higher viscosity oil has more resistance to flow. Thus, resulting in low performance of the engine, especially at low temperature.

The 5w20 is the preferable one for colder climates. While in warmer climates 5w30 is much better. To sum up, we suggest you choose your oil according to your climate.


The thickness of oil is directly related to its viscosity. The higher oil rating number signifies a thicker oil. the thicker the oil is. And lower rating number results in thinner oil. Thicker oil tends to flow less smoothly.

In this scenario, the 5w30 is much thicker than the 5w20. This means the 5w30 will drag more throughout the engine parts. Resulting in more hindrance to the flow of oil.

Whereas, the 5w20 will move much freely through the parts of the engine. The better fluidity of the 5w20 will result in better engine performance. 

Therefore, it’s better to use 5w20 to get expected performance from your engine.

Output Horsepower

Thicker oil creates more resistance to the flow. So, it will take more time to get desired output while using thicker oil. Meaning, you will receive a lot less output for using thicker oil.

5w30 is much thicker than 5w20. The time 5w30 will take to produce a certain output will be a lot. In comparison, the 5w20 will give you the same output in less time.

So, this increase in output makes 5w20 more desirable oil.

Fuel Economy

Fuel economy is an important metric of a vehicle. It is the ratio of distance traveled to the fuel consumed by a vehicle.

Higher fuel economy means you’ll need less oil to reach a destination. 

Usually, thicker oil lowers the fuel economy. The thicker oil between the two discussed is the 5w30. So, using 5w30 will result in lower fuel economy. Meaning, you’ll have to use more oil to get your desired output.

However, the 5w20 is much thinner than the 5w30. This means the amount of oil you will need while using 5w20 is much less.

According to this, 5w20 will give you much better fuel economy. So, we suggest using this oil in your engine.


The durability of oil indicates its resistance to breaking down. Thinner oils under higher temperatures break down very easily. Because the cohesion between the molecules is very low.

So, in hotter conditions, 5w20 will break down comparatively easily. On the contrary, the thicker oil like 5w30 will stay resilient. Thus, making it more desirable in warmer climates.

So, if you are in warmer conditions 5w30 will serve you longer.

Engine Protection

Thicker oil provides more support to the engine. In hotter climates, the 5w20 tends to damage the engine. As it has more additives with it. This makes the engine less efficient and often results in engine failure.

On the other hand, 5w30 provides better engine protection under hotter conditions. This offers relatively superior protection for the engine. The engine runs more smoothly while using this oil under warm conditions. 

To conclude, for smooth and comfortable driving, you should use 5w30 in high temperatures. 

Can I Use 5w20 Instead of 5w30?

You might have this question in mind too. The answer will not differ. Theoretically, you can. But, if your engine is made for 5w30, it’ll not run properly with 5w20. Because the 5w30 is thicker than the 5w20. It might not shatter your engine but will make driving more uncomfortable.

The amount of protection 5w30 gives can not be provided by 5w20. So, you’ll have to change your oil more frequently than before.

What Happens If I Put 5w30 Instead of 5w20 and Vice Versa?

Furthermore, you might be curious about this thing. Well, this concern is super close to your engine’s well-being. So, let’s know this in detail-

The answer is simple. Using 5w30 instead of 5w20 may create problems for the engine’s internal parts. It also will result in lower performance output.

The amount of oil you’ll need will be more than before. This will cause lower fuel economy. This will also affect your engine’s efficiency, ride quality.

Using 5w20 instead of 5w30 will reduce your engine’s performance. The creation of sludge inside your engine might be a result of this.

So, practically, it’s better not to interchange between 5w30 and 5w20. Even automotive experts have the same verdict as well.

Some Alternatives You Can Use

So, you can’t use 5w30 instead of 5w20. But you might need to change your oil immediately. This dilemma can be solved temporarily if you try out a few alternatives.

We’ve mentioned some of them here- 

Alternative 1: Mix 5w30 with 5w20

Wondering: can I mix 5w30 with 5w20

Well, yes. But should only do this if you are out of other alternatives. You can mix your 5w30 oil with a bit of 5w20 oil. 

These oils don’t have a glaring difference in viscosity. Thus, they are quite compatible. But remember, this is not a usual case.

While mixing make sure you use the same manufacturer’s products. Also, check the API service level and the formula. Both of them must be the same or really close. 

Alternative 2: Use 0w20 Instead of 5w20

We suggest using 0w20 instead of 5w30, as an alternative to 5w20. The 0w20 and 5w20 will be at the appropriate range of viscosity. 

The viscosity rating at operating temperature is the same for both of them. This means there won’t be many problems while using 0w20 instead of 5w20.

But this can only be done if there are no other alternatives.


Question: What happens if I put the wrong oil in my car?

Answer: Your car might overheat if you put the wrong oil in your car. Overheating will be caused by poor lubrication. Finally, it will cause transmission failure. The damage will be too severe to reverse. Even a mechanic might not be able to do it.

Question: Which oil is better for high mileage cars?

Answer: Comparatively thicker oil protects worn engine bearings to a great extent. Thicker oil will serve you well till you hear knocking in your engine. You can get more miles than expected by doing this.

Question: Which is better, high mileage oil or synthetic oil?

Answer: This actually depends on how long you’ve used your car. If your car is older, high mileage oil is preferable. If your car is relatively younger, then use synthetic oil for better performance


Well, this is the end of the line. We have gathered everything on- can I use 5w30 instead of 5w20.

Hopefully, we could remove your confusion. You can always try the alternatives if necessary.

Best of luck! We hope you found the right solution for your engine.


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