Can I Switch to 5w30 Oil in my Subaru? Pros and Cons to Consider

As a responsible owner of a Subaru vehicle, it’s vital to ensure that the engine runs smoothly for a long time. One way to maintain engine performance is to use the right engine oil by following the manufacturer’s recommendations. However, at times, it might be tempting to use a different oil type, like 5w30 instead of 0w20.

This article aims to provide car owners with essential information to help them make an informed decision about using 5w30 oil, what each oil is best suited for, and the potential pros and cons of using this substitute.

Understanding Oil Types and Viscosity Grades

To understand the difference between 0w20 and 5w30, it’s essential to understand oil types and viscosity grades. Viscosity refers to how well an oil flows at particular temperatures. The Society of Automotive Engineers (SAE) has developed a grading system, depending on how an engine oil performs in low and high temperature.

The W in oil grades stands for "winter." It’s critical because it determines how the oil flows when the engine starts in cold weather. The lower the number, the better the oil can flow in frigid temperatures. For example, 0w20 oil will flow faster than 5w30 during startup, ensuring that the engine’s critical parts get lubricated instantly. However, as the engine warms up and operates at higher temperatures, the oil’s viscosity becomes an essential factor.

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0w20 is a synthetic oil that is formulated to work best in modern engines that require low viscosity, providing excellent fuel economy and engine protection in colder climates. It’s designed to minimize engine wear by providing a lubricating layer on critical engine parts, maintaining engine longevity.

5w30 is a conventional oil that provides enhanced viscosity at high temperatures. It’s a thicker oil that doesn’t flow as easily during startup. However, it can maintain its protective layer when the engine is operating at high temperatures, making it ideal in warmer temperatures.

Is it Safe to Use 5w30 Oil in a Subaru Vehicle?

Subaru has designed each engine to work correctly with specific oil viscosity, and in most cases, recommends 0w20 oil. Filling the engine with a different oil type will alter the oil’s operating properties, leading to potential issues.

Using 5w30 oil would affect the engine’s fuel economy, and it can reduce the engine’s power. The oil’s thickness prevents it from flowing quickly, leading to increased engine friction and lower fuel economy. It can further lead to increased wear on the engine and negatively impact the engine’s performance and lifespan.

It’s critical to follow the manufacturer’s recommendations to ensure maximum engine protection, reduce engine wear and tear, and minimize the likelihood of warranty issues. In most cases, a car manufacturer designs the engine to work with certain oil type and viscosity grade based on the engine’s hardware, software, and material.

Pros and Cons of Using 5w30 Oil in a Subaru vehicle


  • It’s a more affordable oil option, and it’s readily available in gas stations, auto shops, and retail stores.

  • It’s compatible with most car engines and can work well in warmer temperatures, offering excellent performance in challenging driving conditions.

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  • Using 5w30 could negatively impact the engine’s fuel economy, leading to reduced gas mileage and additional expenses.

  • It could impact engine power and performance, leading to a reduction in the car’s overall performance level.

  • It could lead to decreased engine lubrication, thereby causing engine damages, lower engine longevity and potentially increasing the risk of engine failure.


Q: Can I use 5w30 in my older Subaru model?

A: It depends on the Subaru model’s requirements and engine age. It’s best to stick with the manufacturer’s recommended type of oil. Consult your car owner manual or contact the Subaru dealerships for guidance.

Q: What are the potential issues of not following the manufacturer’s recommendation?

A: Using a different oil type could cause engine malfunction, reduced performance, and wear and tear, eventually reducing the engine’s longevity. Further, it could impact the overall car’s safety and warranty concerns.

Q: How often should I change engine oil in my Subaru vehicle?

A: Subarus typically require an oil change every 5,000 miles or six months, depending on how and where you drive your car. Consult your service manual to know your vehicle’s recommended oil change interval.


It might be tempting to switch to 5w30 oil to save a few dollars. However, it’s crucial to consider the potential consequences of using this alternative oil type. Using the wrong oil type can lead to significant engine expenses, a reduction in fuel economy, and other negative impacts on car performance.

It’s critical to follow the manufacturer’s recommendations when it comes to engine oil type and viscosity. This ensures optimal engine performance, maximum engine protection, and minimizing the potential risks of using the wrong type of oil. Remember that taking care of your vehicle’s engine will increase your car’s lifespan and ensure a safe driving experience.

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Billy Covington

With a passion for all things automotive, Billy is our go-to expert on Subaru performance upgrades and modifications. He's been featured in several car magazines and blogs, and his extensive knowledge and expertise make him a valuable member of our team. When he's not working on cars, he enjoys playing guitar and writing music.

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