2020 Subaru Forester Fluid Type Specifications

Quick Reference

Fluid	Type/Spec	Capacity (approximate)
Engine Oil	0W-20, API SN Plus or SP, ILSAC GF-5 or GF-6	4.8 US Quarts
Engine Coolant	Subaru Super Coolant (Blue), Phosphate Hybrid Organic Acid Technology (P-HOAT)	7.9 US Quarts
Transmission Fluid (CVT)	Subaru CVTF-II	12.9 US Quarts
Front Differential	Subaru Extra MT Gear Oil 75W-80 or equivalent GL-5	1.4 US Quarts
Rear Differential	Subaru Extra MT Gear Oil 75W-80 or equivalent GL-5	0.8 US Quarts
Brake Fluid	DOT 3 or DOT 4	Varies
Power Steering	Electric Power Steering (No Fluid)	N/A
Washer Fluid	Subaru Windshield Washer Fluid or equivalent all-season	0.9 US Gallons

Engine Oil

For your 2020 Subaru Forester, the manufacturer specifies 0W-20 viscosity engine oil. It is crucial to use oil that meets or exceeds API SN Plus or SP standards and is ILSAC GF-5 or GF-6 certified. These specifications ensure the oil provides adequate protection against low-speed pre-ignition (LSPI), a common issue in modern turbocharged direct-injection engines. The 2020 Forester, with its FB25D direct-injection engine, benefits greatly from these advanced oil formulations.

The typical oil capacity for the 2020 Subaru Forester is approximately 4.8 US quarts when performing an oil and filter change. Always verify the exact capacity in your owner's manual, as slight variations can occur based on the specific engine and model year within the generation.

Intervals: Subaru recommends engine oil and filter changes every 6,000 miles or 6 months, whichever comes first. However, if you frequently drive in severe conditions (e.g., extreme temperatures, dusty environments, heavy towing, or extensive idling), more frequent changes may be beneficial.

Common Pitfalls: Never use an oil with a different viscosity or a lower API/ILSAC rating than specified. Using conventional oil or an outdated specification can lead to increased engine wear, reduced fuel economy, and potential damage, including LSPI. Look for the "starburst" symbol on the oil container, indicating ILSAC certification.

Engine Coolant

The 2020 Subaru Forester requires Subaru Super Coolant (Blue), which is a Phosphate Hybrid Organic Acid Technology (P-HOAT) coolant. It is pre-mixed and has a distinct blue color. This specific formulation is designed to provide long-life corrosion protection for Subaru's aluminum engine components and should not be mixed with other coolant types.

The cooling system capacity for the 2020 Forester is approximately 7.9 US quarts. When performing a coolant flush and refill, ensure the system is properly bled to remove air pockets, which can cause overheating.

Intervals: Subaru Super Coolant is a long-life coolant, with an initial replacement interval typically at 137,500 miles or 11 years, followed by subsequent changes every 75,000 miles or 6 years. Always refer to your owner's manual for the precise recommended service schedule.

Common Pitfalls: Mixing different types of coolants (e.g., OAT, HOAT, IAT) can lead to chemical reactions that cause gel formation, corrosion, and damage to the cooling system components. Always use Subaru Super Coolant or an exact P-HOAT equivalent from a reputable manufacturer. Never use conventional green or universal coolants.

Transmission Fluid (CVT)

The 2020 Subaru Forester is equipped with a Lineartronic Continuously Variable Transmission (CVT). This transmission requires a very specific fluid: Subaru CVTF-II. It is critical to use only this fluid or an authorized equivalent that explicitly states compatibility with Subaru CVTF-II. Using an incorrect CVT fluid can severely damage the transmission and void your warranty.

The approximate capacity for a drained and refilled CVT is around 12.9 US quarts. However, a full flush can require more. CVT fluid changes are complex and often require specialized equipment and diagnostic tools to ensure the correct fluid level and temperature.

Intervals: Subaru generally considers the CVT fluid to be a "lifetime" fill under normal driving conditions. However, many technicians and enthusiasts recommend inspecting or changing the fluid every 60,000 miles, especially if the vehicle is regularly subjected to heavy loads, towing, or severe driving conditions. Consult your owner's manual for the official Subaru maintenance schedule.

Common Pitfalls: Never use conventional automatic transmission fluid (ATF) or a "universal" CVT fluid unless it explicitly states compatibility with Subaru CVTF-II. The friction modifiers and viscosity characteristics of CVT fluids are unique and essential for the proper operation and longevity of the CVT.

Front Differential Fluid

For the front differential in your 2020 Subaru Forester, the factory specification calls for Subaru Extra MT Gear Oil 75W-80 or an equivalent GL-5 specification gear oil. This is a hypoid gear oil designed to withstand the extreme pressures found in differential gears.

The capacity of the front differential is approximately 1.4 US quarts.

Intervals: Subaru typically recommends inspecting the differential fluid every 30,000 miles and replacing it every 60,000 miles or 6 years, especially for vehicles driven in severe conditions.

Common Pitfalls: Ensure the gear oil meets the GL-5 specification for hypoid gears. Using a lower GL rating (e.g., GL-4) can lead to premature wear of the differential components.

Rear Differential Fluid

Similar to the front differential, the rear differential of the 2020 Subaru Forester also requires Subaru Extra MT Gear Oil 75W-80 or an equivalent GL-5 specification gear oil.

Expected capacity for the rear differential is around 0.8 US quarts.

Intervals: The maintenance schedule for the rear differential fluid is generally the same as the front: inspect every 30,000 miles and replace every 60,000 miles or 6 years, particularly under severe use.

Common Pitfalls: Again, stick to the GL-5 specification. Some rear differentials (not typically on the 2020 Forester) might require friction modifiers for limited-slip differentials, but for the standard Forester, the GL-5 75W-80 is appropriate.

Brake Fluid

The 2020 Subaru Forester uses either DOT 3 or DOT 4 brake fluid. DOT 4 fluid has a higher wet and dry boiling point than DOT 3, offering a slight performance advantage and increased resistance to brake fade, especially under heavy braking or in high-heat conditions. You can safely upgrade from DOT 3 to DOT 4, but never downgrade from DOT 4 to DOT 3 if DOT 4 was originally specified.

Brake fluid capacity varies as it fills the master cylinder, lines, calipers, and wheel cylinders. When bleeding the brakes, more fluid will be used.

Intervals: Brake fluid is hygroscopic, meaning it absorbs moisture over time, which lowers its boiling point and can lead to internal corrosion. Subaru generally recommends flushing and replacing the brake fluid every 30,000 miles or every 2-3 years, regardless of mileage.

Common Pitfalls: Never use DOT 5 (silicone-based) brake fluid in a system designed for DOT 3 or DOT 4 (glycol-based) fluid, as they are not compatible and can cause serious damage to the braking system. Ensure the brake fluid container is sealed before use, as opened fluid can absorb moisture from the air.

Power Steering Fluid

The 2020 Subaru Forester is equipped with an Electric Power Steering (EPS) system. Therefore, there is no power steering fluid to check or replace. The system relies on an electric motor to assist the steering, eliminating the need for a hydraulic pump, fluid reservoir, and associated hoses.

Washer Fluid

For the windshield washer system, the 2020 Subaru Forester requires Subaru Windshield Washer Fluid or an equivalent all-season washer fluid. Choose a fluid that offers good cleaning performance and freeze protection suitable for your climate. Many aftermarket options include bug remover or de-icing agents, which can be beneficial.

The washer fluid reservoir capacity is approximately 0.9 US gallons.

Intervals: Replenish as needed. It's a good practice to keep the reservoir full, especially before long trips.

Common Pitfalls: Avoid using plain water, especially in freezing temperatures, as it can freeze and damage the washer fluid reservoir, pump, and lines. Using household cleaners (e.g., dish soap) can leave streaks and damage the vehicle's paint finish.

Diesel Exhaust Fluid (DEF)

The 2020 Subaru Forester is exclusively offered with a gasoline engine in the North American market. Therefore, it does not use Diesel Exhaust Fluid (DEF).

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