Choosing the right synthetic oil is a critical decision for any Subaru owner. The unique boxer engine design demands a high-quality lubricant that can protect its horizontally-opposed components from wear, deposits, and heat. With so many options on the market, finding the perfect 0W-20 oil for your vehicle’s specific needs can feel overwhelming.
This guide simplifies your search by presenting a curated list of top-tier synthetic oils. We have evaluated products from trusted OEM and aftermarket brands to help you make an informed decision. Whether you prioritize factory specifications, extended drain intervals, or high-mileage protection, there is an ideal oil here for your Subaru.
Our Top Picks for Subaru 0W-20 Synthetic Oil
- Subaru Synthetic Motor Oil SAE 0W-20 5 Quart
- Genuine Subaru SOA427V1310 Oil – 0W20 Synthetic
- Valvoline Advanced Full Synthetic SAE 0W-20 Motor Oil
- Valvoline Extended Protection Full Synthetic 0W-20
- Valvoline Full Synthetic High Mileage with MaxLife
- Mobil 1 Extended Performance Full Synthetic Motor Oil
- Kirkland Signature 0W-20 Full Synthetic Motor Oil
- Idemitsu IFG 3 0W-20 Motor Oil Full Synthetic
- Pennzoil Platinum Full Synthetic 0W-20 Motor Oil
Subaru Synthetic Motor Oil SAE 0W-20 5 Quart
For Subaru owners who want absolute certainty that their oil meets factory specifications, the Genuine Subaru Synthetic Motor Oil is the definitive choice. This oil is engineered specifically for Subaru boxer engines, ensuring optimal performance and protection for models like the Ascent and Crosstrek. Using the OEM product provides confidence that all manufacturer requirements for viscosity, additive packages, and performance are precisely met.
This formulation is designed to promote a cleaner running engine and contribute to a longer engine life. It offers increased protection against varnish and deposits, which is vital for maintaining the health of complex engine components over time. For those who prefer to stick with the brand’s own lubricant for peace of mind, this 5-quart container is the most straightforward and reliable option.
Genuine Subaru SOA427V1310 Oil – 0W20 Synthetic
This single-quart bottle of Genuine Subaru Synthetic Oil is perfect for topping off your engine or for use in smaller oil changes. It contains the same factory-formulated oil as the larger container, guaranteeing compatibility and protection for your Subaru’s engine. Keeping a bottle on hand ensures you can maintain the correct oil level with the exact lubricant your vehicle was designed to use.
The oil is engineered to provide a cleaner running engine and support a longer engine lifespan. Its formulation specifically works to increase protection against harmful varnish and deposits that can accumulate over time. This product is an essential item for any Subaru owner’s garage, providing the convenience of a genuine part for routine maintenance.
Valvoline Advanced Full Synthetic SAE 0W-20 Motor Oil
Valvoline Advanced Full Synthetic offers robust, all-around protection for modern engines. Its formula is built to defend against the four primary causes of engine breakdown: wear, friction, heat, and deposits. This makes it a strong and reliable choice for daily driving and the varied demands placed on a Subaru’s boxer engine.
A key benefit of this oil is its exceptional defense against water intrusion, which is 24 times stronger than the industry-leading synthetic motor oil. This property is crucial for fighting rust and corrosion, helping to maximize your vehicle’s life. With 40% better wear protection versus industry standards, this oil provides a significant safety margin for your engine’s critical components.
Valvoline Extended Protection Full Synthetic 0W-20
For those who push their oil change intervals or simply want the highest level of defense, Valvoline Extended Protection is an excellent option. It provides ultimate protection against wear, friction, heat, and deposits. This formulation is designed for drivers who need their oil to perform reliably over longer periods.
Like its Advanced sibling, this oil features 24 times stronger protection against water intrusion to combat rust and corrosion. Its Dual Defense Additive Technology works to keep your engine clean and running at peak performance. This dual-action approach supports optimal fuel economy and consistent power output, making it a smart choice for long-term engine health.
Valvoline Full Synthetic High Mileage with MaxLife
If your Subaru has over 75,000 miles on the odometer, the Valvoline High Mileage formula is specifically engineered for your vehicle. Its full synthetic formula uses Enhanced MaxLife Technology to address the unique challenges of older engines. It helps prevent engine breakdown by conditioning aging seals and components.
The oil includes seal conditioners to help prevent and treat existing oil leaks, a common issue in higher-mileage vehicles. It also works to minimize oil consumption and maximize engine life. With 50% better wear protection and 25% extra defense against deposits and sludge, this oil provides targeted care for engines in their later years.
Mobil 1 Extended Performance Full Synthetic Motor Oil
Mobil 1 Extended Performance is renowned for its long-drain capabilities, offering protection for up to 20,000 miles between oil changes. It controls oxidation to prevent oil breakdown and maintains excellent viscosity throughout its service life. This makes it a great choice for drivers who cover long distances or prefer extended maintenance schedules.
The oil utilizes Mobil 1’s Triple Action+ Formula to deliver a combination of engine performance, protection, and cleanliness. It also meets the latest ILSAC GF-6 standards, which means it provides protection against low-speed pre-ignition (LSPI) and timing chain wear. These features help keep your engine clean and can contribute to improved fuel economy.
Kirkland Signature 0W-20 Full Synthetic Motor Oil
Kirkland Signature Full Synthetic Motor Oil offers a compelling balance of quality and value. It is a full synthetic 0W-20 oil that meets the industry’s latest performance standards, making it a suitable and cost-effective choice for your Subaru. Many users report reliable performance that matches more expensive brands.
This oil is designed to provide the necessary protection for modern engines, helping to reduce wear and maintain engine cleanliness. For budget-conscious Subaru owners who do not want to compromise on the fundamental protection of a full synthetic oil, Kirkland Signature presents a very practical option for routine oil changes.
Idemitsu IFG 3 0W-20 Motor Oil Full Synthetic
Idemitsu is a major lubricant supplier to Japanese automakers, giving their IFG 3 oil a strong pedigree for use in Asian vehicles like Subaru. This premium engine oil is SP/GF-6A certified, meeting the requirements for all modern TGDI and PFI engines. Its ISO and IATF certifications further assure maximum reliability and performance.
The oil is specifically engineered to enhance fuel efficiency by reducing friction within the engine. It also provides superior protection against engine wear and minimizes deposit formation, even under extreme driving conditions. For owners who want an oil with a direct connection to Japanese engineering standards, Idemitsu is a top-tier selection.
Pennzoil Platinum Full Synthetic 0W-20 Motor Oil
Pennzoil Platinum Full Synthetic is known for its use of a unique base oil derived from natural gas. This process results in a motor oil with fewer impurities compared to traditional crude oil-based products. The result is an oil that provides excellent performance in key areas critical to engine longevity.
This formulation is designed to keep pistons cleaner than the required industry standards, as tested in the latest Sequence VH sludge test. It also provides superior protection against horsepower loss and friction, helping your engine run efficiently and powerfully. For Subaru owners interested in a technologically advanced synthetic oil, Pennzoil Platinum is a strong contender.
What to Look For in the Best 9W-20 Synthetic Oil for Subaru
As a Subaru owner, I know that finding the right oil isn’t just about keeping the engine running; it’s about protecting that unique boxer engine that gives our cars their character. While 5W-30 is common, some newer models, particularly in specific markets, call for a 9W-20 grade. This can feel a bit niche, so knowing what to look for is key.
First and foremost, you need an oil that meets the official Subaru standards. Look for an API “SP” certification, which is the current industry standard for gasoline engines. More importantly, check for ILSAC GF-6. This is a non-negotiable for most modern Subarus. Some high-performance synthetic oils might also carry additional manufacturer approvals, which is a great sign of quality. Using an oil that doesn’t meet these specifications can lead to premature wear, especially in the turbocharged models like the WRX or Ascent.
The type of synthetic base oil matters. You’ll see terms like full synthetic and synthetic blend. For the demanding conditions a Subaru engine operates under—especially with the horizontal layout—I always recommend a full synthetic. It simply offers better protection against thermal breakdown, sludge formation, and wear over the long haul. It flows better at cold starts, which is when a lot of engine wear happens, and it stands up to high temperatures better, protecting critical components like the turbocharger.
Consider the additive package. A good synthetic oil for your Subaru will have robust detergents to keep the engine clean and dispersants to hold any contaminants in suspension until your next oil change. Look for oils that specifically mention protection against low-speed pre-ignition (LSPI) if you have a turbocharged direct-injection engine—this is a big deal for modern forced-induction motors. Anti-wear additives are also crucial for protecting camshafts, bearings, and other moving parts that work hard in the boxer configuration.
Finally, think about your specific driving style. If you do a lot of short trips, your oil may not get hot enough to burn off condensation and fuel dilution. In that case, an oil with strong TBN (Total Base Number) to fight acidity is smart. If you tow or drive in very hot climates, look for an oil with a high HTHS (High-Temperature High-Shear) viscosity rating for better film strength. Choosing the best 9W-20 synthetic oil for Subaru means matching the oil’s capabilities to your engine’s needs and your own driving habits.
FAQ
Is 9W-20 the correct oil for my Subaru?
You must always consult your owner’s manual for the definitive answer. While 5W-30 is the most common recommendation for Subarus in North America, some newer models in other global markets or specific model years are factory-filled with 9W-20. Using the wrong viscosity can affect fuel economy, emissions, and most importantly, engine longevity. The manual is the final authority.
Can I switch between 5W-30 and 9W-20?
I would not recommend switching back and forth arbitrarily. Your engine was designed with a specific oil viscosity in mind to ensure proper oil pressure, flow, and protection across all operating temperatures. If your manual specifies 9W-20, stick with it. Switching to a thicker oil like 5W-30 without a good reason could lead to reduced fuel efficiency and potentially inadequate flow at startup in cold weather.
What are the benefits of using a full synthetic 9W-20 oil?
Full synthetic oils provide superior performance in almost every way compared to conventional or synthetic blends. They offer better cold-start flow for instant protection, resist breaking down under the high heat of the boxer engine, and contain a more advanced additive package to prevent sludge and deposits. For the relatively tight tolerances and specific needs of a Subaru engine, the extra protection of a full synthetic is a wise investment.
How often should I change my 9W-20 synthetic oil?
Again, your owner’s manual has the official service interval, which is typically around 6,000 miles for normal driving conditions. However, if you frequently make short trips, drive in extreme temperatures, or do a lot of stop-and-go city driving, you might consider changing it more frequently, perhaps every 5,000 miles. The best practice is to check your oil level regularly and note its color and consistency.
Will using 9W-20 synthetic oil improve my gas mileage?
Yes, that’s one of the primary reasons manufacturers are moving towards lower-viscosity oils like 0W-20 and 9W-20. A thinner oil creates less internal friction within the engine, which can lead to a slight improvement in fuel economy. This is part of the broader industry effort to meet stricter emissions and efficiency standards. When searching for the best 9W-20 synthetic oil for Subaru, you are selecting a product designed to support this efficiency.
Are all 9W-20 synthetic oils basically the same?
No, they are not. While they must meet certain minimum industry standards (like API SP), the quality of the base oils and the specific blend of additives can vary significantly between brands. Some oils are formulated with extra anti-wear additives, better detergents, or enhanced protection for turbochargers. It’s worth researching brands that have a strong reputation for quality and, if possible, those that have specific manufacturer approvals.