Choosing the correct 2018 Subaru Forester oil type is fundamental to ensuring the longevity and peak performance of your crossover. This specific model year, available with either the standard Subaru BOXER engine or the turbocharged variant, requires specific attention to viscosity and certification standards. Using the wrong grade can lead to decreased fuel economy, increased engine wear, and potentially costly repairs down the line.
Understanding the 2018 Forester Powertrain
The heart of the 2018 Forester lies in its horizontally-opposed engine design, known as the BOXER. This unique layout provides a low center of gravity for superior handling. For the 2018 model year, Subaru offered two primary options: the naturally aspirated 2.5-liter FB25 and the turbocharged 2.0-liter FA20F. The oil type requirements differ slightly between these engines, making it essential to verify your specific configuration before purchasing lubricants.
Viscosity Grades: The First Critical Specification
Viscosity, or thickness, is the primary characteristic to look for when selecting oil for your 2018 Forester. This specification ensures the oil flows correctly at cold startup and maintains a stable film at high operating temperatures. For most conditions, the recommended viscosity is 5W-30. This multi-grade oil provides excellent cold-flow properties for easy winter starts while offering stable protection during summer heat. However, if you frequently tow heavy loads or drive in extreme climates, consulting your dealer about 0W-20 or 5W-40 alternatives is advisable.
Turbocharged Engine Considerations
If your 2018 Forester is equipped with the turbocharged FA20F engine, the stakes are higher regarding lubrication. Turbochargers spin at incredibly high speeds and generate significant heat, placing immense stress on the oil. Subaru specifically mandates the use of synthetic oil for this engine. Conventional or semi-synthetic blends will break down too quickly, risking premature turbocharger failure. Always ensure your oil meets the required dexos1 or ILSAC GF-6 standard to handle these thermal stresses.
API Service Standards and Certification
Beyond viscosity, the oil must meet specific performance standards set by the American Petroleum Institute (API) and the International Lubricant Standardization and Approval Committee (ILSAC). For the 2018 Forester, you should prioritize oils labeled as meeting API SN or the newer API SP standard. These certifications guarantee the oil has the necessary detergent and anti-wear additives to keep the BOXER engine clean and protected from sludge buildup. Using an uncertified oil can void your powertrain warranty and accelerate internal damage.
The Role of Synthetic Blend vs. Full Synthetic
While the turbocharged model requires full synthetic oil, owners of the naturally aspirated 2.5-liter engine have more flexibility. However, opting for a full synthetic oil is highly recommended for optimal protection. Full synthetic formulations offer superior oxidation resistance, meaning they last longer between oil changes—often extending intervals to 10,000 miles under ideal conditions. They also provide better fuel economy and enhanced cold-weather performance compared to conventional blends, making them the superior choice for long-term vehicle care.
Oil Capacity and Change Procedure
When performing an oil change on your 2018 Forester, it is crucial to use the correct amount of lubricant to avoid overfilling or underfilling the crankcase. The typical oil capacity for this model is approximately 4.4 quarts for the 2.5-liter engine and 3.7 quarts for the 2.0-liter turbocharged engine. Always replace the drain plug gasket and the cabin air filter during service. Utilizing a high-quality oil filter ensures that contaminants are trapped effectively, allowing the new oil to circulate cleanly throughout the engine.
