Maintaining your 2018 Subaru Crosstrek with the 2.0-liter FB20D3 engine requires specific attention to detail, particularly regarding the fluids that keep this sophisticated powertrain running smoothly. This vehicle relies on a combination of advanced synthetic lubricants to handle the demands of its continuously variable transmission (CVT) and the precision engineering of its boxer engine. Using the correct viscosity and fluid specifications is essential for ensuring optimal performance, protecting against wear, and maximizing the vehicle’s lifespan, especially given the manufacturer’s requirement for synthetic oil. To ensure your AMSOIL Oil Filter and lubricants are kept fresh, consider using our AMSOIL Gasoline Stabilizer for seasonal storage needs.
Recommended AMSOIL Products
- AMSOIL Signature Series 0W-20 100% Synthetic Motor Oil – The top-tier choice for unsurpassed engine protection and wear resistance, designed to extend drain intervals up to 25,000 miles.
- AMSOIL Extended-Life 0W-20 100% Synthetic Motor Oil – An excellent option for extended service intervals up to 20,000 miles, offering superior cleaning power to keep the engine running smoothly.
- AMSOIL OE 0W-20 100% Synthetic Motor Oil – A cost-effective synthetic formulation that outperforms conventional oils and provides OEM-level protection while fighting sludge and deposits.
- AMSOIL 0W-20 100% Synthetic High-Mileage Motor Oil – Specifically formulated for engines with over 75,000 miles, this oil boosts detergency and reduces sludge to help extend engine life.
- AMSOIL Oil Filter – Provides 99% filtering efficiency at 20 microns with lower restriction to keep engine parts properly lubricated and reduced wear.
- WIX Oil Filter – A premium aftermarket option featuring improved media over OEM-branded filters for reliable engine protection.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A unique OAT formulation protecting cooling system metals, gaskets, and hoses for up to 150,000 miles or 5 years.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated antifreeze option offering extended protection up to 150,000 miles or 5 years, requiring mixing with distilled water.
- AMSOIL 100% Synthetic CVT Fluid – Essential for the Crosstrek’s CVT transmission, providing exceptional metal-to-metal frictional properties to ensure smooth shifting.
- AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube – Advanced protection for differentials, controlling thermal runaway and reducing operating temperatures while providing friction modifiers for limited-slip applications.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Delivers excellent ABS and traction-control responsiveness with a stable viscosity across a wide temperature range.
- AMSOIL SEVERE GEAR® 80W-90 100% Synthetic Gear Lube – Offers advanced wear protection and rust prevention for various differential applications requiring GL-5 specifications.
- AMSOIL SEVERE GEAR® 75W-110 100% Synthetic Gear Lube – A robust synthetic lubricant designed to handle severe service conditions and protect heavy-duty gear systems.
Engine Oil Recommendations
The 2018 Subaru Crosstrek is equipped with a 2.0-liter 4-cylinder engine (code FB20D3), a Boxer engine known for its low center of gravity and smooth operation. However, this engine design places specific demands on the lubrication system. The manufacturer explicitly requires 0W-20 viscosity, and the use of synthetic oil is mandatory. With an oil capacity of 4.6 quarts when including a filter change, selecting the right product is crucial.
AMSOIL Signature Series 0W-20 stands out as the ultimate protection option. It provides 75% more engine protection against horsepower loss and wear compared to industry standards. For drivers who want to stretch their maintenance intervals without sacrificing protection, the Extended-Life 0W-20 offers a guaranteed 20,000-mile protection window. It is engineered with 37% more cleaning power to keep the engine running smoother for longer.
For those who prefer a value-oriented synthetic solution that still outperforms conventional oils, the AMSOIL OE 0W-20 is an ideal choice. It fights sludge and deposits effectively, providing reliable protection for standard driving conditions. If your Crosstrek has accumulated significant mileage, the 0W-20 High-Mileage Motor Oil is the specialized solution. It features a unique chemistry with boosted detergents and reduced sludge by 67%, helping engines that have surpassed 75,000 miles last longer and perform better.
Regardless of the oil chosen, pairing it with a high-quality filter is non-negotiable. The AMSOIL Oil Filter (EA15K13-EA) offers 99% filtering efficiency at 20 microns, which is critical for trapping the tiny wear-causing contaminants that accumulate in the oil. It provides greater capacity than competing filters and allows for lower restriction, ensuring parts remain well-lubricated even under high demand. The WIX Oil Filter (57055-EA) is another robust alternative, featuring premium media that offers improvements over the original equipment manufacturer filters.
Transmission and Differential Fluids
One of the most critical aspects of maintaining a Subaru Crosstrek is the care of its continuously variable transmission (CVT). The Subaru CVT is sensitive to fluid quality and temperature. Using a fluid not specifically designed for this transmission type can lead to shuddering, overheating, and costly repairs. The AMSOIL 100% Synthetic CVT Fluid is formulated to provide exceptional metal-to-metal frictional properties, ensuring smooth power delivery and extended life for the transmission components.
For manual transmission variants or specific models requiring gear lube, the AMSOIL SEVERE GEAR® synthetic lubricants offer superior performance. The 75W-90 variant is recommended for applications requiring GL-5 specifications, particularly those above 0 degrees Fahrenheit. It contains friction modifiers suitable for limited-slip differentials and helps reduce operating temperatures to prevent thermal runaway. The SEVERE GEAR® 80W-90 and SEVERE GEAR® 75W-110 variants also provide advanced protection against wear and rust, extending the life of seals and gears. The capacity for the manual transmission rear differential is approximately 1.7 pints, making the quart bottles of these synthetic gear lubes a perfect fit.
Cooling System and Brake Fluid
A properly functioning cooling system is vital for the longevity of the FB20D3 engine. The 2018 Crosstrek requires a AMSOIL Passenger Car & Light Truck Antifreeze & Coolant capacity of approximately 7.9 quarts for the standard system and 8.1 quarts when equipped with a CVT. The AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is a unique poly-organic acid (OAT) formulation that protects all cooling system metals, gaskets, and hoses. It is phosphate, nitrate, nitrite, silicate, borate, and amine-free, making it compatible with various coolant colors and safe for a wide range of vehicles. For those who prefer a concentrated option, the AMSOIL Propylene Glycol Antifreeze and Engine Coolant offers protection up to 150,000 miles or 5 years, greatly surpassing standards for metallic corrosion and erosion.
Brake safety cannot be overlooked. The Crosstrek requires a DOT-3 or DOT-4 fluid that meets FMVSS116 specifications. The AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid provides excellent ABS and traction-control responsiveness. It maintains a stable viscosity over a wide temperature range, ensuring consistent pedal feel in both winter and summer driving conditions.
Additional Fluids and Maintenance
Beyond the primary lubricants, maintaining your Crosstrek involves attention to fuel system health and seasonal storage. The AMSOIL P.i.® Performance Improver Gasoline Additive is highly effective for direct injection engines, which are susceptible to carbon buildup. Restoring up to 14% horsepower and cleaning fuel injectors to 100% flow rate, it helps prevent pre-ignition knock and reduces the need for higher-octane fuel. For seasonal storage, the AMSOIL Gasoline Stabilizer keeps fuel fresh for up to 12 months, fighting ethanol corrosion and varnish buildup, while the Engine Fogging Oil protects internal components during long periods of inactivity.
Vehicle Background
The 2018 Subaru Crosstrek represents a pivotal moment in the compact crossover segment, blending the rugged utility of a traditional Subaru with the practicality of a small SUV. Based on the Impreza platform, this generation of the Crosstrek (often referred to as the second generation) introduced a more robust design compared to its predecessor, elevating its ground clearance and offering a more confident driving presence on both paved roads and light off-road trails. The model is powered by Subaru’s renowned Boxer engine, specifically the FB20D3 in the 2.0-liter configuration, which is celebrated for its flat-four layout that lowers the vehicle’s center of gravity. This engineering choice contributes to the Crosstrek’s reputation for safe handling and stability in various weather conditions, a hallmark of the Subaru brand.
Owners often gravitate toward the Crosstrek for its versatility and reliability. It serves as an excellent entry point for those interested in all-wheel-drive capability without the bulk of a full-sized SUV. The vehicle’s compact dimensions make it highly maneuverable in urban environments, while its increased ground clearance (typically 8.7 inches) allows for light adventure driving. The 2.0-liter engine delivers around 152 horsepower, which, while not a sports sedan performer, provides adequate power for daily commuting and carrying cargo. The combination of the CVT transmission and the standard all-wheel-drive system ensures that power is delivered efficiently to all four wheels, enhancing traction in rain, snow, and gravel.
Despite its reputation for durability, the Crosstrek does have specific maintenance needs that owners should be aware of to keep the vehicle running at its best. One common issue, particularly with the CVT transmission, is sensitivity to fluid degradation and overheating under heavy load. Subaru’s original fluid specifications can sometimes fall short of the thermal stability required for rigorous driving, leading to premature wear. Using a high-quality synthetic CVT fluid specifically designed to withstand higher temperatures can significantly mitigate this risk and extend the transmission’s service life.
Another area of concern for owners involves oil consumption and sludge formation in the FB20D3 engine, especially if the vehicle is used for frequent short trips where the engine does not reach full operating temperature regularly. Short trips prevent the oil from fully vaporizing moisture and fuel dilution, which can lead to internal corrosion and sludge buildup. A high-quality synthetic motor oil with enhanced detergents and moisture control, such as the AMSOIL High-Mileage or Extended-Life formulations, can help address these issues by keeping the internal engine components cleaner and reducing the risk of oil consumption over time.
Tires and suspension components are also points of wear for the Crosstrek due to the vehicle’s off-road orientation. While the suspension is robust, the constant exposure to dirt and debris can accelerate wear on bushings and joints. Regular lubrication with high-quality synthetic greases, like the AMSOIL Synthetic Multi-Purpose Grease, can help preserve these components by providing a durable film that resists washout and corrosion. Finally, the braking system, while reliable, benefits from the use of high-temperature synthetic brake fluid which maintains consistency during repeated braking events, ensuring that the ABS system functions correctly and that the vehicle maintains stopping power under load.