2021 Subaru Forester Oil Capacity & Filter Spec Guide

The 2021 Subaru Forester takes 4.4 US quarts (4.2 liters) of 0W-20 full synthetic engine oil.

Quick Answer

• Oil Capacity: 4.4 US quarts (4.2 liters)
• Recommended Oil Weight: 0W-20 Full Synthetic
• Oil Specification: API SN PLUS or later, ILSAC GF-5 or later
• OEM Oil Filter: Subaru P/N 15208AA170 (or 15208AA150, 15208AA160, 15208AA170, 15208AA12A – confirm with dealer)
• Aftermarket Oil Filter Cross-Reference:
  • Fram: PH6607
  • Wix: 57055
  • Mobil 1: M1-108A

Capacity by Engine Option

For the 2021 Subaru Forester, there is typically only one engine option in most markets:

Oil Change Interval

Subaru recommends the following oil change intervals for the 2021 Forester:

• Normal Driving Conditions: Every 6,000 miles or 6 months, whichever comes first.
• Severe Driving Conditions: Every 3,000 miles or 3 months, whichever comes first.

Severe driving conditions include:

• Repeated short-distance driving.
• Driving in dusty conditions.
• Driving in extremely cold weather.
• Frequent trailer towing or heavy loads.
• Driving in mountainous areas.

Adhering to the severe duty interval under these conditions is crucial for engine longevity.

Drain Plug Torque

The oil drain plug for the 2021 Subaru Forester should be torqued to 30 ft-lbs (approximately 41 Nm).

Always use a new crush washer with each oil change to ensure a proper seal and prevent leaks. The OEM crush washer has a Subaru part number of 803916010.

How to Change the Oil

Changing the oil on your 2021 Subaru Forester is a straightforward process:

1. Warm up the engine: Drive the vehicle for 5-10 minutes to bring the oil to operating temperature, ensuring it drains more easily.
2. Park and secure: Park on a level surface, engage the parking brake, and safely lift the front of the vehicle using a jack and jack stands.
3. Locate drain plug: Place a suitable drain pan beneath the oil pan. Using a 17mm wrench or socket, carefully remove the drain plug.
4. Drain oil: Allow all the old oil to drain completely. This can take 10-15 minutes.
5. Replace crush washer and drain plug: Install a new crush washer on the drain plug and reinsert it into the oil pan. Torque to 30 ft-lbs.
6. Remove old filter: Position the drain pan under the oil filter. Using an oil filter wrench, loosen and remove the old oil filter. Be prepared for a small amount of oil to spill.
7. Install new filter: Apply a thin film of new engine oil to the gasket of the new oil filter. Screw it on by hand until snug, then tighten an additional 3/4 to 1 full turn (or follow filter manufacturer instructions).
8. Add new oil: Remove the oil filler cap on top of the engine. Carefully pour in approximately 4 quarts of the recommended 0W-20 oil. Wait a few minutes for the oil to settle.
9. Check oil level: With the vehicle on level ground, check the dipstick. Add small amounts of oil as needed until the level is between the "low" and "full" marks on the dipstick.
10. Start engine and recheck: Start the engine and let it run for a minute to circulate the new oil. Turn it off, wait a few minutes, and recheck the dipstick. Top off if necessary.
11. Reset maintenance light: Consult your owner's manual for instructions on how to reset the oil maintenance reminder light.

Common Issues / Tips for this Generation (SK Forester, 2019-Present)

• CVT Fluid: While not directly related to engine oil, remember that the Forester's Lineartronic CVT fluid also requires periodic inspection and replacement. Consult your owner's manual for the specific interval, as it's often longer than the engine oil interval.
• Oil Consumption: Some Subaru FB engines have been known to exhibit minor oil consumption. It's always a good practice to check your oil level regularly (e.g., once a month or every few fuel stops) between oil changes, especially if you drive in severe conditions.
• Starlink Updates: Ensure your Starlink infotainment system is up to date, as software glitches can sometimes be mistaken for mechanical issues. Dealer visits can usually resolve these.
• EyeSight Calibration: If your windshield is replaced or damaged, proper EyeSight camera calibration is critical for the safety system to function correctly. This is often a dealer-only procedure.

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