The 1987 Subaru Justy with the 1.2-liter three-cylinder EA12 engine is a compact vehicle that demands precise maintenance to ensure longevity. Proper lubrication is critical for this engine, as it was designed with specific tolerances that synthetic oils can better accommodate than conventional alternatives. Using the correct viscosity and quality fluids helps maintain oil pressure, reduces wear on internal components, and ensures reliable performance in varying temperature conditions. Whether you are driving in extreme heat or cold, or simply want to extend the intervals between services, selecting the right AMSOIL motor oils provides a significant advantage for the longevity of your Justy.
Recommended AMSOIL Products
- AMSOIL Signature Series 10W-30 100% Synthetic Motor Oil – Offers unsurpassed protection with a formula that reduces horsepower loss and wear. This oil is the top choice for the 1987 Subaru Justy EA12 engine, providing up to 25,000 miles of protection between changes.
- AMSOIL Extended-Life 10W-30 100% Synthetic Motor Oil – A cost-effective option that still delivers 100% synthetic performance. It features enhanced cleaning power to keep the engine running smoothly and provides up to 20,000 miles of protection.
- AMSOIL OE 10W-30 100% Synthetic Motor Oil – Specifically formulated to outperform conventional oils regarding OEM mileage requirements. This fluid fights sludge and deposits while maintaining the engine’s cleanliness over time.
- AMSOIL 10W-30 100% Synthetic High-Mileage Motor Oil – An ideal solution for Justy engines with over 75,000 miles. It features a unique chemistry to reduce sludge and boost detergents, helping older engines perform better.
- AMSOIL Oil Filter EA15K20 – Designed with premium media to provide 99% filtration efficiency at 20 microns. This filter allows lower restriction, keeping engine parts lubricated and reducing wear from contaminants.
- WIX Oil Filter 51334 – A premium media option that offers improvements over original equipment manufacturer branded filters. It serves as an excellent alternative filter choice for this vehicle.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – This 50/50 pre-mix formulation protects all cooling system metals, gaskets, and hoses. It offers protection for up to 150,000 miles or 5 years.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated coolant that requires mixing with water. It delivers superior protection against corrosion and erosion, suitable for long service intervals.
- AMSOIL Signature Series Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – Designed to withstand heavy towing and elevated temperatures. It remains fluid in sub-zero conditions, providing a reserve of protection for automatic transmissions.
- AMSOIL OE Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – Provides excellent cold-weather performance and resists harmful sludge. This fluid promotes smooth, shudder-free shifts and guards against leaks.
- AMSOIL 75W-90 Manual Transmission & Transaxle Gear Lube – A friction-modified fluid that protects brass synchronizers and resists rust. It offers outstanding cold-flow properties for manual transmissions in the Justy.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Features excellent responsiveness for ABS and traction control systems. Its stable viscosity ensures reliable braking performance across a wide temperature range.
- AMSOIL SEVERE GEAR® 80W-90 100% Synthetic Gear Lube – Provides advanced protection against wear and helps control thermal runaway. It contains friction modifiers suitable for limited-slip applications.
- AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube – Offers all-temperature protection for the rear differential. It helps reduce operating temperatures and extends the life of seals and equipment.
- AMSOIL SEVERE GEAR® 75W-110 100% Synthetic Gear Lube – A heavier viscosity option for the differential, providing robust protection against wear and rust under severe conditions.
When performing maintenance on the 1987 Subaru Justy, understanding the specific fluid requirements is essential for optimal operation. The engine oil capacity is 3.0 quarts when the filter is replaced, and it is crucial to check the oil level after refilling. The oil drain plug should be torqued between 30 and 35 ft/lbs. For cooling, the system holds 4.8 quarts of antifreeze. Choosing a high-quality synthetic coolant prevents rust and corrosion within the cooling system, which is vital for older vehicles. The transmission specifications vary slightly depending on whether the vehicle is Front-Wheel Drive (FWD) or Four-Wheel Drive (4WD). The automatic transmission requires approximately 3.6 quarts for a total fill in FWD models and 4.3 quarts for 4WD models. Manual transmissions require specific GL-4 fluid, with capacities ranging from 4.9 pints for FWD models to 7 pints for 4WD models. The rear differential typically holds 1.7 pints of AMSOIL 75W-90 Manual Transmission & Transaxle Gear Lube.
One of the primary benefits of using AMSOIL synthetic motor oil in this vehicle is the extended service interval capability. While conventional oils may break down more quickly, AMSOIL products can protect the engine for up to 25,000 miles or one year, provided the vehicle is not operated under severe service conditions. This longevity helps reduce the total cost of ownership by decreasing the frequency of oil changes and the associated labor. Additionally, the high-detergent packages found in these oils help clean the engine over time, removing deposits that can restrict oil flow and cause premature wear. The high-mileage formula is particularly beneficial for Justy owners with significant mileage on their odometers, as it is designed to condition seals to reduce oil consumption and leaks.
Vehicle Background
The 1987 Subaru Justy represents an interesting era in automotive history, marking a time when Japanese manufacturers were redefining the concept of the subcompact car. Produced by Fuji Heavy Industries, the company that later became known as Subaru Corporation, the Justy was designed to be a fuel-efficient, compact hatchback that could easily navigate narrow urban streets while remaining economical for daily commuting. The model featured a front-engine, front-wheel-drive layout, which was a standard and efficient configuration for its class, although 4WD options were eventually introduced in later years to expand its utility.
Powered by the 1.2-liter three-cylinder EA12 engine, the Justy was a marvel of packaging, offering a surprisingly spacious interior for its tiny footprint. The EA12 engine was a simple, air-cooled (in earlier iterations) or water-cooled unit, depending on the specific production year and market, though by 1987, the water-cooled variant was the standard. It delivered modest horsepower, prioritizing fuel economy and reliability over raw power. This made it a popular choice for city dwellers and those looking for a second car or an economical first vehicle. The engine’s design emphasized longevity, making it suitable for high-mileage driving if maintained with quality lubricants. The Justy’s suspension was tuned for comfort, providing a smooth ride that belied its small size.
Owners of the 1987 Justy often cite its durability and ease of maintenance as key reasons for keeping the vehicle on the road. However, like any aging machine, there are common issues that can arise. One potential problem involves oil consumption, which can occur in higher-mileage units as piston rings and valve seals wear. Switching to a synthetic high-mileage motor oil can help mitigate this issue by conditioning the seals and reducing burning. Another common concern is the degradation of cooling system components, such as hoses and radiators, which can lead to overheating. Using a high-quality antifreeze with extended protection can help prevent corrosion and maintain the integrity of the cooling system.
Additionally, the manual transmission in the Justy can develop synchronizer wear over time, leading to grinding gears during shifts. This is often exacerbated by old, contaminated fluid. Regular fluid changes with a proper GL-4 manual transmission oil can help restore smooth shifting and protect the brass synchronizers. Finally, brake fade or a soft pedal feel can occur as the DOT 3 AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid absorbs moisture over the decades. Flushing the system and replacing it with a high-performance synthetic brake fluid can restore firm pedal feel and ensure consistent braking performance in all weather conditions.
For those who still drive this classic subcompact, keeping it running smoothly is a rewarding endeavor. The combination of a well-maintained EA12 engine and high-quality fluids ensures that the 1987 Subaru Justy remains a reliable and efficient companion on the road. By adhering to the recommended fluid specifications and using premium synthetic lubricants, owners can maximize the vehicle’s lifespan and enjoy its unique driving characteristics for years to come.