Can I Mix 5W-30 with 5W-20?

Last Updated on May 23, 2023 by QCity Editorial Stuff

It is generally not recommended to mix different viscosity grades of engine oil, such as mixing 5W-30 with 5W-20. Engine oil viscosity refers to its thickness or resistance to flow, and different viscosity grades are formulated to meet the specific requirements of different engines.

Understanding Motor Oil Viscosity

When it comes to motor oil, viscosity is an important factor to consider. The numbers on the oil bottle represent its viscosity, or how thick or thin the oil is. 5W-20 and 5W-30 are two common types of engine oils, and many drivers wonder if they can mix the two.

  • The first number in the oil name stands for “winter,” indicating the oil’s viscosity in colder temperatures. The second number represents the oil’s viscosity when the engine is operating at normal temperatures. Generally, 5W-30 oil is a better choice for most cars as it has a higher viscosity, making it better at lubricating the engine.
  • Although it is possible to mix 5W-20 and 5W-30 engine oils, it is not recommended. Mixing the two oils can reduce the benefits of each oil. The 5W-30 oil will thin out the 5W-20 oil and not flow as well in colder temperatures. On the other hand, the 5W-20 oil will make the 5W-30 oil thicker and less effective in warmer temperatures.

Detailed characteristics of 5W-30 motor oil

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  • Motor oil is an essential element to keep your engine running smoothly. For a car engine, proper lubrication is necessary, especially when dealing with different weather conditions.
  • Two popular engine oils, 5W-20 and 5W-30, have different properties that make them ideal in specific situations. While both oils share similar viscosity ratings, they have different ranges of viscosity for both hot and cold weather.
  • In general, 5W-20 is lighter and more fluid, which means it flows better in colder weather, whereas 5W-30 is thicker and more viscous, which makes it better for warmer climates and high-performance engines.
  • According to expert advice, for colder weather, it’s best to use 5W-20 oil that is thinner and flows more quickly, which ensures that the engine has proper lubrication during start-up. On the other hand, if you are driving in warmer climes, 5W-30 oil can offer better protection as it reduces wear and tear and can handle high temperatures more efficiently.
  • While it’s generally recommended to use the recommended grade of oil in your car, it’s safe to mix 5W-20 and 5W-30 engine oils. However, it’s not the best idea. Mixing the two types of oil won’t damage the engine, but it’s not the best way to ensure optimal protection and performance.
  • Using the wrong type of oil can cause many problems, from decreased engine efficiency to increased wear and tear, and, in some cases, engine failure. So always follow the car manufacturer’s recommendations or consult a qualified professional before making any oil changes.

Finally, different manufacturers offer different standards and qualities of oil, which affects oil performance and usage. Therefore, it’s always advisable to use the same manufacturer and stay consistent with the oil to get better results and extend your engine’s life. [3][4]

Detailed characteristics of 5W-20 motor oil

  • Understanding the viscosity of 5W-20 motor oil

5W-20 motor oil is a type of engine oil that has become increasingly popular in recent years. The “5W” stands for the oil’s winter viscosity rating, meaning how easily the oil flows at colder temperatures. The “20” refers to the oil’s viscosity rating at 100°C, indicating how well it can perform at higher temperatures. This oil has a lower viscosity compared to 5W-30, making it ideal for use in colder weather conditions.

  • Benefits of using 5W-20 motor oil:

One of the main benefits of using 5W-20 motor oil is that it provides improved fuel economy. This oil reduces engine friction, which leads to improved engine efficiency and increased fuel economy. Another advantage is that it helps improve cold start performance, making it easier to start the engine in chilly weather conditions. This oil also provides excellent engine protection, helping to reduce wear, tear, and engine breakdowns.

Compatibility of 5W-30 and 5W-20 Motor Oils

  • Motor oil is crucial for the health and longevity of a car’s engine. The type and viscosity of oil needed for a specific car vary based on the manufacturer’s recommendations. One common question about engine oil is whether 5W-30 and 5W-20 can be mixed.
  • Combining 5W-20 and 5W-30 oils is possible, but it’s not the most advisable option. While there will be no immediate issues, the engine’s long-term health could be affected. The brands and service levels of the oils should be similar to prevent damage to the engine. For urgent situations, getting both oils from the same brand can be helpful.
  • If both oils contain different viscosity and additives, they cannot be thoroughly mixed to make a single oil blend. Manufacturers usually discourage using a 5W-30 oil in a 5W-20 engine because it’s too thick, leading to wear and tear, overheating, and oil starvation. However, if mixing oils is required, the higher ratio should be the recommended oil type.
  • The owner’s manual holds the best ratio to use to avoid any engine damage; users should stick to the manufacturer’s recommendation. The biggest difference between 5W-30 and 5W-20 oils is their viscosity, as 5W-20 is thinner and flows more easily in colder temperatures. 5W-30 oils have a higher viscosity, making them better for higher temperatures.

Can 5W-30 and 5W-20 be mixed?

The answer is yes, but with some considerations. Both oils have the same viscosity, which allows them to be mixed. However, it’s important to note that 5W-20 oil is thinner and more fluid, making it ideal for colder temperatures, while 5W-30 is thicker and better suited for hotter conditions.

It’s safe to mix the oils as long as it’s done in optimal conditions. If the weather is too hot or too cold, it’s best to use only one type of oil that is suitable for those conditions. Car manuals typically recommend an oil type, and if only one type is recommended, it’s best to stick with it to prolong the engine’s life.

Effects of Mixing 5W-30 with 5W-20

Mixing oils is a common question among drivers, especially when they have different oils in their garage. One of the frequently asked questions is, can I mix 5W-30 with 5W-20? In this article, we will discuss the effects of mixing these two oils and how you can do it safely.

Mixing 5W-30 with 5W-20 will not cause any immediate issues with your engine. However, once the two oils start blending together and creating a hybrid, the performance of the oil in your engine will depend on the blend’s viscosity index. The lack of matching viscosity indexes can lead to decreased oil pressure, abnormal wear, and decreased fuel efficiency.


When it comes to choosing the right oil for your engine, it’s important to know the difference between the various types. Specifically, mixing different types of engine oil can cause problems, but is it safe to mix 5W-30 with 5W-20? According to factual data, the answer is yes, but with some caveats. Both oils have the same viscosity, so they can be mixed together without damaging your engine. However, it’s important to consult your vehicle’s owner’s manual to determine which oil grade is recommended. Some engines require lighter oil for colder weather conditions while others need heavier oil to provide better protection against wear.


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