The 2018 Subaru FORESTER equipped with the turbocharged 2.0L FA20F2 engine is a performance-oriented compact SUV known for its reliability, yet it demands precise lubrication to maintain its longevity. Because this turbocharged boxer engine operates under higher thermal and mechanical stress than naturally aspirated units, using the correct synthetic motor oil is essential to prevent turbocharger failure and ensure smooth operation in extreme temperatures. Proper lubrication extends service intervals, reduces wear, and protects critical components from the unique challenges of Subaru’s Symmetrical Drive system and turbocharged powertrain.
Recommended AMSOIL Products
- AMSOIL Signature Series 5W-30 100% Synthetic Motor Oil – Offers unsurpassed engine protection for up to 25,000 miles, designed to handle the extreme heat of the turbocharger while minimizing horsepower loss.
- AMSOIL Extended-Life 5W-30 100% Synthetic Motor Oil – Provides 37% more cleaning power to keep the engine running smoother for up to 20,000 miles between changes.
- AMSOIL OE 5W-30 100% Synthetic Motor Oil – Fights sludge and deposits with a formulation trusted by professional engine builders, protecting turbochargers effectively.
- AMSOIL 5W-30 100% Synthetic High-Mileage Motor Oil – Formulated specifically for vehicles with over 75,000 miles to reduce sludge and boost cleaning power.
- AMSOIL Oil Filter – Delivers 99% filtration efficiency at 20 microns with greater capacity for contaminants than competing filters.
- WIX Oil Filter – Offers premium media improvements over original equipment manufacturer-branded filters for reliable engine protection.
- WIX Air Filter – Premium media ensures the turbocharged engine receives clean air, maximizing performance and fuel efficiency.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A unique poly-organic acid formulation that protects against corrosion for up to 150,000 miles.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated solution that greatly surpasses standards for metallic corrosion and erosion protection.
- AMSOIL 100% Synthetic CVT Fluid – Provides exceptional metal-to-metal frictional properties for the Subaru Lineartronic transmission.
- AMSOIL SEVERE GEAR® 80W-90 100% Synthetic Gear Lube – Ideal for the rear differential with GL-5 ratings, controlling thermal runaway and reducing operating temperatures.
- AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube – Advanced protection against wear for the rear differential, featuring friction modifiers for limited-slip applications.
- AMSOIL SEVERE GEAR® 75W-110 100% Synthetic Gear Lube – Designed for extreme pressure conditions, ensuring long oil and seal life in the differentials.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Delivers excellent ABS and traction-control responsiveness with a stable viscosity over a wide temperature range.
Understanding the specific requirements of the 2018 FORESTER is key to maintaining its performance. The 2.0-liter FA20F2 turbocharged engine is the heart of this vehicle, demanding an oil that can handle high turbocharger speeds and elevated temperatures. The engine oil capacity for this model is 5.4 quarts when the filter is replaced, requiring a total of approximately 5.4 quarts of fluid to refill. It is crucial to note that synthetic oil is required for this engine. After refilling, the oil level should be checked to ensure proper lubrication. The drain plug should be torqued to 31 ft/lbs with a new washer installed. Failing to use the correct viscosity or type of oil can lead to premature wear on the turbocharger bearings and piston rings.
Beyond the engine, the transmission system of the 2018 FORESTER often utilizes a Lineartronic CVT (Continuously Variable Transmission). The automatic transmission fluid capacity for the TR580 model is a substantial 12.7 quarts for a total fill. Using a standard transmission fluid here can lead to shuddering, overheating, and premature failure. AMSOIL 100% Synthetic CVT Fluid is engineered specifically for these applications, providing the necessary frictional properties to ensure smooth power delivery and protect internal components from wear. This fluid helps maintain the precise friction coefficients required for the metal-to-metal contact points inside the CVT, which is critical for the longevity of the transmission.
The Subaru’s All-Wheel Drive system also relies on precise lubrication. The rear differential requires specific gear lube, with a capacity of 1.7 pints. Depending on the specific configuration and temperature ranges encountered, AMSOIL offers SEVERE GEAR® in 80W-90, 75W-90, and 75W-110 viscosities. These synthetic gear lubes contain friction modifiers suitable for limited-slip differentials and control thermal runaway, a common issue in high-stress AWD systems. Additionally, the braking system benefits from AMSOIL DOT 3 and DOT 4 Synthetic Brake Fluid, which maintains a high boiling point and ensures consistent pedal feel, essential for a vehicle that sees performance driving and off-road use.
Cooling is another vital aspect of the 2018 FORESTER’s maintenance. With a coolant capacity of 9.5 quarts, the cooling system must be protected against both freezing in winter and boiling over in summer. AMSOIL’s antifreeze and coolant products utilize unique organic acid technology (OAT) to protect all cooling system metals, gaskets, and hoses. These formulations are free of phosphates, nitrates, nitrites, silicates, borates, and amines, which can degrade quickly in older radiators or cause foaming issues. Using a high-quality coolant ensures the engine operates at its optimal temperature, preventing overheating and extending the life of the radiator and water pump.
About the Vehicle
The 2018 Subaru FORESTER represents a pivotal generation in the history of the brand’s compact SUV lineup. Built on Subaru’s proprietary Global Platform, this model year marked a shift toward improved rigidity, lower center of gravity, and enhanced safety features. The FORESTER has long been celebrated for its practicality, offering one of the highest rooflines in its class and a boxy design that maximizes interior cargo space. For outdoor enthusiasts and drivers who value utility, the 2018 model stands out as a versatile companion capable of handling both daily commuting and weekend adventures.
At the core of this vehicle’s reputation is the “EyeSight” driver-assist technology, which became a standard safety feature for many trims. This system utilizes dual stereo cameras to monitor the road ahead, helping to prevent collisions through automatic emergency braking, adaptive cruise control, and lane-keeping assist. The 2.0L turbocharged engine, code-named the FA20F2, delivers a spirited driving experience, providing the power needed to keep up with traffic while maintaining the fuel efficiency drivers expect from a Subaru. The engine’s boxer configuration not only lowers the vehicle’s center of gravity but also contributes to a smoother running character with reduced vibration compared to inline or V-type engines.
Despite its robust design, the 2018 FORESTER can encounter specific issues that are common to the FA-series turbo engines and the Subaru CVT transmission. Owners should be aware of potential turbocharger oil starvation, particularly in the early life of the engine or if oil change intervals are extended without using high-quality synthetic oil. Using a high-performance synthetic motor oil like AMSOIL Signature Series helps ensure a steady flow of oil to the turbocharger bearings, reducing the risk of premature wear. Another known issue involves carbon buildup on the intake valves of Direct Injection (GDI) engines, which can lead to rough idling and reduced power. While the 2018 model year marks the transition to DIT, regular maintenance with fuel additives like AMSOIL P.i.® can help keep injectors clean and prevent carbon deposits from affecting performance.
Furthermore, the CVT transmission in the FORESTER can sometimes exhibit shuddering or “hunting” behavior, often attributed to fluid breakdown or contamination. Regular fluid changes using a dedicated synthetic CVT fluid can restore the correct frictional properties and smooth out the transmission’s operation. Finally, rust and corrosion are known concerns for Subaru vehicles in regions with heavy road salt usage. The undercarriage and suspension components of the FORESTER can degrade faster than expected without proper protection. Applying a dedicated rust inhibitor or using synthetic gear lube that contains superior corrosion additives can significantly extend the life of the vehicle’s structural and mechanical components, ensuring the FORESTER remains a reliable and safe vehicle for years to come.
By selecting the right AMSOIL lubricants, owners can address these specific needs, ensuring that the 2018 FORESTER continues to perform at its peak. From the engine oil that protects the turbocharger to the gear lube that safeguards the AWD system, every component benefits from the advanced chemistry of AMSOIL’s synthetic products. Whether for severe service, extreme temperatures, or extended service intervals, these fluids provide the protection necessary to keep the vehicle running smoothly and efficiently. With the correct maintenance regimen, the 2018 Subaru FORESTER remains one of the most capable and reliable options in the compact SUV segment.
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