The 2012 Subaru Legacy equipped with the 3.6-liter flat-six EZ36D engine is renowned for its smooth power delivery and the unique flat-four and flat-six powertrain architecture that defines the brand. To maintain this high level of performance and longevity, selecting the correct lubricants is not merely a maintenance task but a crucial aspect of vehicle care. This engine requires a specific viscosity of synthetic motor oil to handle thermal stress and ensure optimal fuel economy, while the all-wheel-drive system and transmission demand specialized fluids to manage the complex gearing and torque distribution inherent in Subaru’s design.
Recommended AMSOIL Products
- AMSOIL Signature Series 5W-30 100% Synthetic Motor Oil – This premium oil provides unsurpassed engine protection, capable of lasting up to 25,000 miles or one year. It offers 75% more protection against horsepower loss and wear, making it ideal for drivers who want maximum durability and performance from their EZ36D engine.
- AMSOIL Extended-Life 5W-30 100% Synthetic Motor Oil – Designed for extended protection up to 20,000 miles, this oil features 37% more cleaning power to keep the engine running smoothly for longer periods. It also provides excellent protection against Low Speed Pre-Ignition (LSPI) and is a robust choice for routine maintenance intervals.
- AMSOIL OE 5W-30 100% Synthetic Motor Oil – This fluid fights sludge and deposits with its 100% synthetic formulation, protecting turbochargers better than many industry standards. It is a cost-effective option that still delivers full synthetic benefits, outperforming conventional oils and meeting OEM mileage requirements.
- AMSOIL 5W-30 100% Synthetic High-Mileage Motor Oil – Specifically formulated for engines with over 75,000 miles, this oil contains boosted detergents and enhanced anti-wear additives. It reduces sludge by 67% and helps seal aging engine components, offering guaranteed protection for 12,000 miles or one year.
- AMSOIL Oil Filter – This high-efficiency filter offers 99% filtering at 20 microns, significantly greater capacity for small contaminants than competing filters. It is engineered for extended service life to match the synthetic oil it works with, ensuring clean oil circulation throughout the engine.
- WIX Oil Filter – Premium media offers improvements over original equipment manufacturer (OEM)-branded filters for those preferring an OEM-style replacement.
- WIX Air Filter – Premium media offers improvements over original equipment manufacturer (OEM)-branded filters to help ensure proper air flow for your engine.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A unique poly-organic acid (OAT) formulation that provides protection for up to 150,000 miles or five years. This ethylene glycol pre-mix protects all cooling system metals and is compatible with all coolant colors, ensuring your engine maintains the correct operating temperature.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated option that requires mixing with distilled water, offering protection up to 150,000 miles or 5 years for passenger cars.
- AMSOIL Signature Series Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – This fluid withstands the rigors of heavy towing, elevated temperatures, and challenging terrain while remaining fluid in sub-zero conditions. It provides reserve protection during heavy use, ensuring smooth shifts and longevity for the Legacy’s automatic transmission.
- AMSOIL OE Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – Protects against wear, resists harmful sludge, and guards against leaks with excellent cold-weather performance.
- AMSOIL SEVERE GEAR® 80W-90 100% Synthetic Gear Lube – Designed for differentials requiring GL-5 protection, this lube controls thermal runaway and contains friction modifiers for limited-slip applications. It helps reduce operating temperatures and extends the life of oil, seals, and equipment.
- AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube – This premium gear lube is preferred for the Legacy’s front differential and offers advanced wear protection while resisting rust and corrosion. It is suitable for extreme temperature applications and helps reduce operating temperatures for better differential efficiency.
- AMSOIL SEVERE GEAR® 75W-110 100% Synthetic Gear Lube – Another advanced option for heavy-duty gear applications, providing extended life for oil, seals, and equipment.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Providing excellent ABS and traction-control responsiveness, this fluid maintains a stable viscosity over a wide temperature range. It ensures consistent braking performance and protects the hydraulic components of the Subaru’s braking system.
Understanding the specific fluid needs of the 2012 Legacy helps ensure that every component receives the proper treatment. The engine oil capacity for the 3.6L EZ36D engine is 6.9 quarts when performing a change with a filter replacement. It is crucial to check the oil level after refilling and to torque the oil drain plug to the specified 33 ft/lbs, ensuring a new washer is installed on the drain bolt to prevent leaks. While synthetic oil is recommended for optimal protection, it is not strictly required, though the performance benefits of switching to a premium synthetic like Signature Series or Extended-Life are significant.
For cooling systems, the capacity is also 6.9 quarts of antifreeze. Choosing between the ethylene glycol-based Passenger Car & Light Truck Antifreeze & Coolant or the propylene glycol concentrated option depends on your specific preference for pre-mixed convenience versus custom mixing. The transmission fluid capacity for the 5-speed TG5D8 transmission is 10.1 quarts for a total fill. The differential lubrication requirements vary based on whether the differential is Type T, VA-Type, or standard GL-5. The front differential typically requires 3 pints, while the rear differential capacity is 1.7 pints for Type T and VA-Type differentials. Selecting the correct viscosity, such as 75W-90 or 80W-90, ensures the all-wheel-drive system operates smoothly under load.
Vehicle Background
The 2012 Subaru Legacy represents a significant era in the evolution of the brand’s sedan lineup, offering a blend of practicality, safety, and all-wheel-drive capability. Powered by the EJ and EZ series boxer engines, this model year features the robust 3.6-liter horizontally opposed six-cylinder engine, known as the EZ36. This powertrain delivers a balance of torque and refinement that appealed to drivers seeking a comfortable daily driver with the confidence of Subaru’s Symmetrical All-Wheel Drive system. The Legacy has long been a staple in the North American market, often favored by families and outdoor enthusiasts for its raised ground clearance and durability in various weather conditions.
Originating from Japan, Subaru’s engineering philosophy emphasizes safety and reliability, with features like the Boxer engine layout providing a lower center of gravity compared to inline-four engines. This design contributes to better handling and stability, making the 2012 Legacy a capable performer on both highways and winding roads. The EZ36 engine, with its dual overhead camshafts and variable valve timing, provides a smooth power delivery that distinguishes it from the four-cylinder variants. Owners often appreciate the vehicle’s quiet cabin and spacious interior, which supports long-distance travel. The Legacy’s reputation for longevity is supported by regular maintenance, particularly the use of high-quality lubricants that address the specific thermal and mechanical stresses of the flat-six engine and the AWD drivetrain.
Maintaining this vehicle with the correct fluids ensures that the complex interaction between the engine, transmission, and all-wheel-drive system remains seamless. Whether the vehicle is used for daily commuting or weekend excursions, the synthetic motor oils, transmission fluid, gear lube, and grease recommended for the Legacy help mitigate wear, reduce heat, and prevent the buildup of sludge and deposits. By adhering to these lubrication guidelines, owners can extend the service life of their vehicle and maintain its performance characteristics, ensuring that the 2012 Subaru Legacy continues to serve as a reliable and safe transport option for years to come.