2020 Subaru Forester Coolant Capacity & Type

The 2020 Subaru Forester holds approximately 7.6 to 7.9 quarts (7.2 to 7.5 liters) of coolant.

Quick Answer

• Total Cooling System Capacity: 7.6 - 7.9 quarts (7.2 - 7.5 liters)
• OEM Coolant Spec: Subaru Super Coolant (Blue, Long-Life HOAT/P-OAT, specifically formulated for Subaru engines. Subaru Part Number SOA868V9210 or equivalent.)
• Mix Ratio: 50/50 Pre-mix is recommended. If using concentrate, dilute with distilled water to a 50/50 ratio.

Capacity by Engine Option

The 2020 Subaru Forester typically comes with one engine option in most markets, the 2.5L naturally aspirated flat-four engine. The capacity listed above applies to this engine.

Flush Interval

Maintaining your coolant is crucial for the longevity of your engine. For the 2020 Subaru Forester, the recommended coolant flush intervals are:

• Normal Duty: Typically, the first flush is recommended at 137,500 miles or 11 years, whichever comes first. Subsequent flushes are usually recommended every 75,000 miles or 6 years.
• Severe Duty: If you operate your vehicle under severe conditions (e.g., frequent towing, driving in extreme temperatures, dusty conditions, or frequent short trips), it's advisable to inspect your coolant more frequently and consider reducing the flush interval. Consult your owner's manual for specific severe duty recommendations, but a general guideline would be to reduce normal intervals by about 25-50%.

Always refer to your Subaru owner's manual for the most accurate and up-to-date maintenance schedule.

How to Refill & Bleed

Properly refilling and bleeding the cooling system is vital to prevent air pockets, which can lead to overheating. Here's a general procedure for your 2020 Subaru Forester:

1. Safety First: Ensure the engine is completely cool before starting. Wear appropriate safety gear, such as gloves and eye protection.
2. Drain Old Coolant (if performing a flush): Open the petcock on the bottom of the radiator and remove the radiator cap to allow the system to drain. Ensure you have a suitable drain pan to catch the old coolant.
3. Close Drain and Refill: Once drained, close the radiator petcock. Slowly begin to pour the specified Subaru Super Coolant (50/50 mix) into the radiator. Fill until it reaches the top of the filler neck.
4. Fill Reservoir: Fill the coolant reservoir (overflow tank) to the "FULL" line.
5. Bleeding Process:
   • Start the engine with the radiator cap off (or loosely on, depending on design) and the heater on full hot (fan speed low).
   • As the engine warms up, the thermostat will open, and coolant will start to circulate. You may see air bubbles escaping from the radiator filler neck. Continue to top off the radiator as needed.
   • There is typically an air bleed screw on top of the thermostat housing or elsewhere on the engine. Loosen this screw to allow trapped air to escape until a steady stream of coolant comes out.
   • Once no more air bubbles appear, replace the radiator cap securely.
   • Drive the vehicle for a short period, allow it to cool completely, and then recheck the coolant level in the reservoir and radiator. Top up as necessary. You may need to repeat this process a few times over the next few drive cycles to ensure all air is purged.

Special Note: Subaru engines can be particularly prone to air pockets due to their horizontally opposed (boxer) design. A vacuum fill tool is highly recommended for a thorough and efficient bleeding process, especially after a complete drain and flush.

Common Cooling System Issues

While the 2020 Subaru Forester generally has a robust cooling system, some issues can arise, particularly for this generation of Subaru vehicles:

• Radiator Leaks: Over time, the plastic end tanks of the radiator, or the crimp points between the plastic and aluminum core, can become brittle and develop leaks. Keep an eye out for pink or blue residue around these areas.
• Head Gasket Issues (less common in newer models but still a consideration): While significantly improved in later generations, earlier Subaru boxer engines were known for external head gasket leaks. White smoke from the exhaust, unexplained coolant loss, or oil/coolant mixing can be signs of this. The 2020 Forester is less prone, but it's always good to be aware.
• Thermostat Failure: A failing thermostat can cause the engine to run too hot or too cold. Symptoms include erratic temperature gauge readings, prolonged warm-up times, or engine overheating.
• Water Pump Leaks/Failure: The water pump circulates coolant throughout the engine. Bearings can wear out, leading to noise, or seals can fail, causing coolant leaks. A common symptom is a whining or grinding noise from the front of the engine, accompanied by coolant loss.
• Coolant Expansion Tank Cracks: The plastic coolant expansion tank can develop cracks over time, leading to slow coolant leaks. Visually inspect the tank for any hairline cracks or discoloration.
• Hose Degradation: Radiator hoses and heater hoses can harden, crack, or become leaky with age and exposure to heat. Regularly inspect them for signs of wear.

Using the correct type of coolant (Subaru Super Coolant) and adhering to the recommended maintenance schedule can significantly mitigate these issues. Using incorrect coolant can lead to corrosion, premature component failure, and void your warranty.

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