How To Change Motor Oil In Subaru Forester?

By Nick Marchenko, PhD

Updated: September 23, 2023

Ensuring the regular change of motor oil is pivotal for the smooth operation of your Subaru Forester's engine. Oil plays a vital role in lubricating all motor components, providing cooling, and ensuring stable engine performance.

Without oil, the engine could fail within a mere five minutes, leaving it jammed and non-operational. While motor oil is fundamental, it, unfortunately, degrades over time, losing its efficacy.

To safeguard the engine from potential oil damage, timely replacement is essential.

Fortuitously, the oil change process is straightforward, necessitating only a basic grasp of the Subaru Forester's structure. Service stations can complete an oil change quicker than you might finish a cup of coffee!

However, if you're keen on saving some bucks or are a DIY aficionado eager to handle your vehicle’s maintenance, continue reading to learn how to change the motor oil in your Subaru Forester.

Key Takeaways:

• Regular motor oil changes are essential for the optimal operation of the Subaru Forester’s engine.
• The recommended oil change interval for the Subaru Forester varies between 6,000 to 12,000 miles, depending on the oil type.
• Extended usage of degraded engine oil can circulate harmful contaminants, potentially causing engine damage.
• Choosing the correct oil, replacing filters, and responsibly disposing of used motor oil at designated centers is crucial when changing oil.

How often should you change the oil in Subaru Forester?

For passenger vehicles like the Subaru Forester, manufacturers generally recommend changing the engine oil every 6,000 to 9,300 miles.

Regardless of mileage, it's advisable to change the oil at least once a year, even if the Subaru Forester remains unused.

Additionally, specifics on how frequently to change the oil in the Subaru Forester can be found in the vehicle’s service manual. The oil change frequency ultimately hinges on how intensively the Subaru Forester is driven.

We provide a general guideline for the motor oil change intervals below.

Average Subaru Forester oil replacement intervals:

• Conventional oil - recommend changing every 5-7 thousand miles or once a year, whichever comes first;
• Synthetic lubricant - Depending on the composition, synthetic oils can last longer. Semi-synthetic oils are good for about 8-9 thousand miles, while fully synthetic ones can go up to 12 thousand miles. Nonetheless, monitor your engine’s behavior; if anomalies are detected, an oil change might be due;
• Along with the oil, it's wise to replace all filters. The oil filter should be changed with every oil replacement, while swapping out the air and fuel filters is discretionary, but recommended.

Why is it important to change the engine oil in Subaru Forester?

When in operation, the oil interacts with every engine component, collecting impurities such as soot, metal shavings, and carbon deposits. Failing to replace the oil regularly could circulate these contaminants, causing internal engine damage.

Moreover, consistent exposure to high temperatures can cause lower quality lubricants to lose their properties, resulting in inadequate lubrication and potentially leading to various engine issues.

How to choose the proper oil for Subaru Forester?

Selecting the right oil is vital as it can significantly impact engine performance. At first glance, oils might seem indistinguishable, but they differ in several aspects, affecting the engine positively or negatively.

Here are the main considerations when choosing oil for your Subaru Forester:

Price. Opt for oil that suits your budget, but avoid overly cheap options. Counterfeit products are a risk, and the last thing you want is an inferior oil in your engine. Remember, investing in quality oil pays off in the long run:

Manufacturer. Renowned manufacturers are less likely to produce subpar oils. Always buy from certified sellers to avoid counterfeits;

Viscosity. This crucial factor measures the oil's flow resistance. Viscosity is denoted by ratings such as 5W-30, 10W-40, etc.

The number preceding the "W" represents the oil’s viscosity at low temperatures (W stands for Winter), while the succeeding number indicates viscosity at 100°C. Selecting the right viscosity, aligning with your Subaru Forester’s specifications and your regional climate, is paramount.

API Classification and Subaru Forester. The American Petroleum Institute (API) has various oil classifications that suit different engines, like the ones powering your rugged Subaru Forester. API designates oils as "SN", "SM", "SL" for gasoline engines or "CK-4", "CJ-4", and "CI-4" for diesel engines; each tailor-fit for the engine's unique requirements.

Optimized Additives for Subaru Performance. Motor oils, like those suitable for Subaru Forester, often contain essential additives that perform a variety of functions, ensuring your ride remains smooth and efficient:

• Detergent additives: Keep your Subaru's engine clean and efficient;
• Dispersants: Prevent sludge formation ensuring smoother rides;
• Antioxidants: Prevent oil oxidation, essential for prolonging engine life;
• Anti-wear agents: Protect your Subaru's engine parts from wear and tear;
• Corrosion inhibitors: Prevent corrosion, an essential for Subaru Foresters in varying climates;
• Friction modifiers: Improve fuel efficiency – crucial for the adventures your Subaru takes you on!

Type of oil: The oils suitable for Subaru Forester can be mineral, synthetic, or a mixture of both.

• Mineral oils: Obtained directly from crude oil through refining processes;
• Synthetic oils: These are made using chemical processes that provide better performance, especially at extreme temperatures – perfect for Subaru Forester’s versatile applications.

If you aren't sure which oil is suitable for your Subaru Forester, no problem; we’ve got your back. View the list of recommendations here.

For those wanting to dive deeper into selecting the right oil for your Subaru's engine, we have a more detailed guide available. Here is the link.

How to change the oil in Subaru Forester?

Changing motor oil in your Subaru Forester is a breeze, but there are a few things to keep in mind to ensure smooth operation and prevent any potential harm to your vehicle or yourself.

Time required: 30 minutes

Level of difficulty: 2/5

People needed: 1-2

Necessary equipment: 

• A set of wrenches or sockets – essential tools for the task;
• Rag(s) – keep things clean;
• A key for unscrewing the filter or a belt – no oil change without it;
• A container for draining used oil – don’t spill, keep it neat;
• A new oil suitable for Subaru Forester – the lifeline of your engine;
• A new oil filter – keep the new oil clean and your engine happy.

Preparation Setup for Subaru Forester

Before diving into the oil change, consider your attire. Wear something old, or that you won’t mind getting dirty in, because dealing with oil can get a bit messy.

Think about the location where you’ll change the oil. There needs to be ample space for you to work freely under your Subaru Forester. Here are some options:

• Drive your Subaru Forester onto a ramp or into a pit in your garage;
• Lift your vehicle securely or jack it up;
• Ensure that your Subaru Forester is stable – safety first!;
• Allow your Subaru Forester to cool down for at least 10–15 minutes if it has been running – avoid any burns from hot oil!

Locate and unscrew the oil cap on the Subaru Forester

First, unscrew the oil filler cap on your Subaru Forester. It's usually marked with an oil can symbol or simply the word “oil”. Wipe it clean of any oil and dirt if necessary and place it on a clean cloth.

Find the oil drain plug for Subaru Forester

Now, get under your Subaru Forester and locate the drain plug on the engine tray – it resembles a nut. Place a suitable container underneath to catch the old oil. Remember, the container should be large enough to hold all the waste oil, so avoid using anything too small or with a narrow neck. A deep basin or bucket works best.

Unscrew the Oil Plug - Subaru Forester Style

Get a grip on the correct wrench that suits your Subaru Forester’s plug. Initiate the unscrewing process with caution, ensuring not to damage the thread or head, avoiding a whole world of future complications. If resistance is met, an impact wrench can be a lifesaver.

Be on the alert! Once you’re successful, the oil is going to make a quick escape. Have that container in position and keep yourself spotless.

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Drain the Oil - The Forester Way

Patience is key here, wait for the oil to fully drain from your Forester. With the oil filler cap already unscrewed, you’re looking at a matter of minutes.

Inspect the drained oil, any sign of debris or shavings could indicate an engine issue, signaling a visit to your mechanic.

Securing the Oil Plug Back on the Forester

Cleanliness is next to godliness! Wipe off any residual oil from the plug and seat. A dab of degreaser or WD-40 should do the trick. This simple step can save you from a stuck plug in the future.

Refit the plug securely, paying attention to the gasket if it has one, a new one is advised to prevent any potential leaks. The appropriate tightening torque can be found in the Forester’s owner’s manual.

Unscrewing the Oil Filter of a Subaru Forester

Next in line is the oil filter located on the side of the Forester’s engine block. Typically, turning it counterclockwise does the job.

If stubbornness prevails, a leather belt can be your ally in securing a grip to turn it. A special oil filter wrench can also come in handy.

Remember, a residual amount of oil will be in the filter, so be ready with a rag!

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Installing a New Oil Filter in a Subaru Forester

Lubricate the new filter’s seal with some engine oil for ease of installation and future replacements. Securely screw in the new filter, ensuring there’s no wobble or potential for leaks.

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Pour in That Fresh Motor Oil - Forester Ready!

With the plug and filter securely in place, it’s time to pour in that fresh oil. Consult your Subaru Forester’s manual for the correct oil quantity, and keep an eye on the levels using the dipstick. Remember, overfilling is a no-go!

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Disposing of the Used Motor Oil Responsibly

Post oil change, responsible disposal is crucial. Specialized recycling centers are the go-to for eco-friendly disposal, ensuring you’re doing your part for Mother Earth.